Read the advertisements carefully．Thenanswer the questions that follow．

INTERESTED IN CHILDCARE?

Qualified person or preschool teacherneeded for busy childcare center, south of the river．Full-timework guaranteed．Immediatestart necessary．Thecandidate must be able to work as a co-operative team member．Phone6345 2345 for an interview and fax resume to 6345 2345．

WE NEED OFFICE CLEANERS!

Three people are required forprofessional cleaning in the CBD area．Working hours from 5:00 pm on Mondays,Wednesdays & Fridays．Approximately five hours per shift．A goodrecord is necessary．Experiencepreferred．Phone6345 7843 now．

WANT TO WORK AS A DENTAL NURSE?

This is an exciting opportunity for aqualified dental nurse with a confident and cheerful personality to work in theSchool Dental Health Scheme．You must be able to get along well withchildren because the work involves talking to groups about dental healthpractices．Forfurther information, visit our website at: schooldentalservices@ gov．sg．And faxyour resume to 6234 4567．

FLORIST WANTED!

Are you a creative and trained floristwith at least two years of experience? Then this may be just what you areseeking．Thecity's leading Florist Artist Studio needs another part-time member on theirwedding team．Pleasephone 6098 7888 now!

    Imagine you're standing in line to buy a snack at a store. You step up to the counter and the cashier scans your food. Next, you have to pay. but instead of scanning a QR Code（二维码）with your smart phone, you just hold out your hand so the cashier can scan your fingerprint. Or, a camera scans your face, your eyes or even your ear.

    Now, this type of technology might not be far away. As technology companies move away from the traditional password, biometric（生物特征识别的）security, which includes fingerprint, face and voice ID, is becoming increasingly popular.

    In 2013, Apple introduced the iPhone 5s, one of the first smart phones with a fingerprint scanner. Since then, using one's fingerprint to unlock a phone and make mobile payments has become commonplace, bringing convenience to our lives. And since 2016, Samsung has featured eye-scanning technology in its top smart phones, while Apple's new iphone X can even scan a user's face. But despite its popularity, experts warn that biometrics might not be as secure as we imagine. “Biometrics is ideally good in practice, not so much,” said John Michener, a biometrics expert.

    When introducing the new iPhone's face ID feature, Phil Schiller, Apple's senior vice-president, said. “The chance that a random person in the population could look at your iPhones X and unlock it with their face is about one in a million.” But it's already been done. In a video posted on a community website Reddit, two brothers showed how they were each able to unlock the same iPhone X using their own face. And they aren't even twins.

    “We may expect too much from biometrics,” Anil Jain, a computer science professor at Michigan State University, told CBS News. “No security systems are perfect.”

    Earlier last year, Jain found a way to trick biometric security. Using a printed copy of a thumbprint, she was able to unlock a dead person's smart phone for the police, according to a tech website Splinter. “It's good to see biometrics being used more,” Jain told CBS News, “because it adds another factor for security. But using multiple security measures is the best defense.”

    Tornadoes are nature's most violent storms, which can cause deaths and destroy a neighborhood in seconds. A tornado appears as a funnel-shaped (漏斗状) cloud from a thunderstorm to the ground with whirling (飞快移动) winds that can reach 300 miles per hour. Damage paths can be over one mile wide and 50 miles long. Every state is at some risk from this disaster.

    Some tornadoes can be seen clearly, while rain or nearby low-hanging clouds obscure others. At many times, tornadoes develop so rapidly that little, if any, advance warning is possible.

    Before a tornado hits, the air may become very still. A cloud of debris (散片) can mark the location of a tornado even if a funnel can not be seen. Tornadoes generally occur near the edge of a thunderstorm, when the strong wind may die down. It is not uncommon to see clear, sunlit skies behind a tornado.

The following are facts about tornadoes:

    The average forward speed of a tornado is 30 MPH, but may also vary from still to 70 MPH. Debris is picked up or a cloud forms in the funnel.

    The average tornado moves from southwest to northeast, but tornadoes have been known to move in any direction. Tornadoes are most often reported east of the Rocky Mountains during spring and summer months.

    Tornadoes can happen together with tropical storms and hurricanes as they move onto land. Waterspouts are tornadoes that form over water.

    The tornado season in the southern states of America is March through May; in the northern states, it is late spring through early summer. Tornadoes are most likely to occur between 3 p.m. and 9 p.m., but can occur at any time.

    What makes a sense of humor is a difficult thing to tell. Different people find different things funny, and what may seem hilarious to some, will be highly rude to others. However, having some kind of sense of humor is important for reducing stress and getting along with others. Therefore, it's important to think about ways to improve your sense of humor.

    Look for the funny side of situations. While it can be difficult at times to find the funny side in unfortunate events when you're having a bad day, try to think about how the situation might look like to other people, and attempt not to get too angry. Laughing over minor accidents, trips and falls will help you in preventing the loss of temper that you will regret later.

    Learn some basic jokes. Some people find it hard to remember jokes, and feel left out when others are telling them. It's worth trying to learn a few jokes that you can pull out the bag when you need to, or regularly think about how you can turn a funny situation that occurs in daily life into an entertaining anecdote(趣闻) for later.

    Look at joke or humor cards. There are many different kinds of funny cards available, which can be a great inspiration for finding ways to improve your sense of humor. Giving an appropriate funny card to friends and family on the right occasion will show that you have a good sense of humor and are thinking about them.

    Learn from friends. Look at friends that you think have a great sense of humor. How do they deal with situations, and what kind of jokes do they make? Is there anything you can take away from their actions?

    The bus was full of the sounds of laughing and yelling fifth graders. They were on their way to the zoo for a class trip. Mario was excited to see the zoo, but there was one problem. It was ten o'clock in the morning, but his stomach was already grumbling(咕咕叫). He reached down and grabbed his lunch bag. Opening it, he saw that it contained a peanut butter and jelly sandwich, an orange, and two cookies. Mario sighed. He always had peanut butter and jell.

    “Trade you lunches,” he said to the boy seated next to him on the bus．

    “Okay,” said Mark as he handed his brown bag to Mario．

    Mario opened it and was hit with the smell of tuna(金枪鱼). Mario wrinkled his nose and quickly closed the bag. He leaned forward and tapped the shoulder of the girl in front of him.” Swap lunches, Toni?” he asked．

    “Hmm, okay,” said Toni．

    Mario smiled. This was fun. But when he looked into the bag, he frowned. What a disappointment! A ham sandwich, but no cookies! He had to have cookies．

    Mario turned in his seat. “Want to trade lunches?” he asked Juana．

    “Definitely!” said Juana. She grabbed his lunch and tossed hers onto his lap．

    He opened the lunch bag. Pizza! He reached into the bag to grab it. Oh, no! The pizza was hard. He could hit a home run with pizza that hard.

    Mario twisted in his seat. One last try, he told himself. “Hey, Mona! Trade lunches?”

    Three rows behind him, Mona seemed hesitant: Finally, she nodded. She passed her lunch forward, and he passed his back．

    Mario took a deep breath and opened the bag. It was a peanut butter and jelly sandwich, an orange, and two cookies. The sandwich was a little squashed(挤压), and one of the cookies was broken.

    Mario ate it anyway. And it was delicious.

    When I was nine years old, I loved to go fishing with my dad. But the only thing that wasn't very fun about it was that he could catch many fish while I couldn't catch anything. I usually got pretty upset and kept asking him why. He always answered, "Son, if you want to catch a fish, you have to think like a fish." I remember being even more upset then because, "I'm not a fish!" I didn't know how to think like a fish. Besides, I reasoned, how could what I think influence what a fish does?

    As I got a little older I began to understand what my dad really meant. So, I read some books on fish. And I even joined the local fishing club and started attending the monthly meetings. I learned that a fish is a cold-blooded animal and therefore is very sensitive to water temperature. That is why fish prefer shallow water to deep water because the former is warmer. Besides, water is usually warmer in direct sunlight than in the shade. Yet, fish don't have any eyelids (眼皮) and the sun hurts their eyes. The more I understood fish, the more I became effective at finding and catching them.

    When I grew up and entered the business world, I remember hearing my first boss say, "We all need to think like sales people." But it didn't completely make sense. My dad never once said, "If you want to catch a fish you need to think like a fisherman." What he said was, "You need to think like a fish." Years later, with great efforts to promote long-term services to people much older and richer than me, I gradually learned what we all need is to think more like customers. It is not an easy job. I will show you how in the following chapters.