How airplanes fly?

People {#blank#}1{#/blank#} (try) for a long time before they invented a {#blank#}2{#/blank#} (success) "flying machine". Now there {#blank#}3{#/blank#} (be) so many {#blank#}4{#/blank#} (plane) in the sky.

    An airplane {#blank#}5{#/blank#} (fly) because of the upward force(力量) of {#blank#}6{#/blank#} (move) air against its wings(翼). To get that moving air, it needs something {#blank#}7{#/blank#} (push) it forward—like a motor-driven propeller(螺旋桨) or a jet engine(喷气发动机). You can fly a kite if there  {#blank#}8{#/blank#} (be) enough wind to hold it up. An airplane is like a kite with such force!

    More and {#blank#}9{#/blank#} (many) young people are getting to like making model planes now. How about you? Are you interested in it after {#blank#}10{#/blank#} (read) this article?

Today I kept a promise and had lunch with a friend I had not seen for a while. I {#blank#}1{#/blank#} (be) extremely tired from school work, and my 5 hours in art lab where I had just come from, {#blank#}2{#/blank#} I wanted to go home to have a rest. But I kept my promise (48) {#blank#}3{#/blank#}I didn't want to make my friend disappointed. As it turned out, we had such a good time that I stayed{#blank#}4{#/blank#} (long) than I had planned and really saw how much the occasion meant to my friend. We{#blank#}5{#/blank#} (share) a lot of news, and it felt like we had never had such a long break.

I{#blank#}6{#/blank#} (real) wanted to go home and hide under the covers today. But for{#blank#}7{#/blank#} (keep) my promise and going to meet with a friend, I not only was kind to another person, but was also kind to {#blank#}8{#/blank#}. I got some much needed self-care out of the occasion and was able {#blank#}9{#/blank#} (make) the day of another person meaningful — someone {#blank#}10{#/blank#}was busy but still kept his promise to have dinner with me.

— {#blank#}1{#/blank#} 45 minutes.