语法填空。
阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空。
A farmer and his son were taking their ass(驴) to a market. They wanted to sell it. They passed a
group of girls, 1 laughed at how foolish the farmer was to have an ass and 2 (walk), so the farmer
put his son 3 the ass.
Further down the road, they passed some old people who scolded the farmer for allowing his young
son to ride 4 said that he should be riding himself .
Further along the road, they passed some travelers who said that if he wanted to sell the ass the two of
them should carry him 5 the ass would be exhausted and worthless. So the farmer and his son bound
the ass's legs to a pole and carried him.
When they approached the town, people there laughed at the sight of them. The noise was so loud
6 the ass was frightened to 7 (die). He kicked out and 23 (fall) off a bridge into the river and
drowned.
The 9 (embarrass) farmer and son went home with nothing, except the lesson that you will achieve
nothing by trying to please 10 .
=0.6kg的氢气球，因受水平风力的作用，系氢气球的轻绳与水平方向成
角。已知空气对气球的浮力为15N，人的质量
，且人受的浮力忽略不计（sin370=0.6，cos370=0.8）。