Not all memories are sweet. Some people spend all their lives trying to forget bad experiences.

   Now American researchers think they are close to developing a pill, {#blank#}1{#/blank#} will help people forget bad memories. The pill is {#blank#}2{#/blank#}(design)to be taken immediately after a frightening experience. They hope it might reduce, or {#blank#}3{#/blank#}(possible) erase (抹去) the effect of painful memories.

   In November, experts tested a drug on people in the U.S. and France. The drug stops the body from {#blank#}4{#/blank#}(release) chemicals that fix memories in the brain. So far, the research {#blank#}5{#/blank#}(suggest) that only the emotional effects of memories may be reduced, not that memories are wiped out. They are not sure to the degree people's memories are affected.

   The research has caused a great deal of {#blank#}6{#/blank#}(argue). Some think it is {#blank#}7{#/blank#}bad idea, while others support it. Supporters say it could lead to pills which prevent or treat soldiers' troubling memories after war. They say that there are many people who suffer {#blank#}8{#/blank#}terrible memories. {#blank#}9{#/blank#}, those who are against the research say that maybe the pills can change people's memories and changing memories is very {#blank#}10{#/blank#}(danger) because memories give us our identity.

    “Why do we have to learn about these useless things?” This is what teachers have heard students complain about most {#blank#}1{#/blank#} (common). In such cases, we may tell the students such {#blank#}2{#/blank#} story:

    One night, a group of herdsmen（牧民）were about to leave the campsite when there appeared a flash of bright light. They knew that God would be there, so they looked forward to {#blank#}3{#/blank#}(get) wishes from God. God {#blank#}4{#/blank#}(begin)to speak: “You have to collect along the way a number of stones. Tomorrow night, you may be very happy, but you may be very regretful.” Then God disappeared.

    The herdsmen were very {#blank#}5{#/blank#}(disappoint), because they would look forward to God to bring them untold wealth or treasure, but they did not expect that God had told them to do all these meaningful things. However, in any case, after all, that was God's will. Although there {#blank#}6{#/blank#} (be) some dissatisfaction, they were still picking over some stones. {#blank#}7{#/blank#} this way, they took a day. When night fell, they stopped. All of a sudden, they found that all the stones they picked had turned into {#blank#}8{#/blank#} (diamond). They were happy, {#blank#}9{#/blank#} at the same time, they felt very sorry, and they regretted that they had not collected more stones.

    Now we feel that knowledge is as useless as stones, {#blank#}10{#/blank#} may become endless wealth in the future.

    With a timid voice, the little boy greeted his father as he returned from work, "Daddy, how much do you make an hour?"

    Greatly {#blank#}1{#/blank#} (surprise), the father said, "Look, son, not even your mother knows that. Don't bother me now, I'm tired."

    "But Daddy, just tell me please! How much do you make an hour," the boy insisted.

    The father, {#blank#}2{#/blank#} (final) giving up, replied, "Twenty dollars per hour."

    "Okay, Daddy? Could you loan me ten dollars?" the boy asked.

    Showing his restlessness, the father yelled, "So that was the reason {#blank#}3{#/blank#} you asked how much I earn, right? Go to sleep and don't bother me any longer!"

    It was already dark and the father was thinking about what he {#blank#}4{#/blank#} (say) and was feeling guilty. Maybe he thought his son wanted to buy something. Finally, trying to ease {#blank#}5{#/blank#} (he) mind, the father went to his son's room.

    "Are you {#blank#}6{#/blank#} (sleep), son?" asked the father.

    "No, Daddy. Why?" replied the boy.

    "Here's the money you asked for {#blank#}7{#/blank#} (early)," the father said.

    "Thanks, Daddy!" replied the son happily, putting his hand under his pillow and removing some money. "Now I have enough! Now I have twenty dollars!" the boy said to his father, who was gazing at his son, confused {#blank#}8{#/blank#} what his son had just said.

    "Daddy, could you sell me one hour of your time?"

    Time is {#blank#}9{#/blank#} precious to spend it all on work! Appreciate your loved {#blank#}10{#/blank#} (one) and don't take them for granted.