用括号内所给动词的适当形式填空，必要时可加助动词或情态动词。
The first chocolatc was enjoyed by the people in Central and South America hundreds of years
ago. In those days, the cocoa bean (可可豆)was used to make a chocolate drink. Much later, it
_1 _ (bring) to Europe.
In 1824, Mr Cadbury opened a small shop in the United Kingdom. He sold chocolate drink. In
1831, he opened a factory to make chocolate drink. Mr Cadbury believed that wine was bad and he
wanted 2_ (encourage) people to drink chocolate instead. A few years later, a man _3_ (invent)
a way to make chocolate bars (块), and so people had the chance to eat chocolate instead of only
drinking it.
At first only dark chocolate was made. Milk chocolate came later and it was made by __4_ (add)
milk to the chocolate. Mr Cadbury made their first milk chocolate bar in 1897. Their most famous
chocolate, Cadbury Milk Bar, was made in 1905. It _ 5 (be) popular for over 100 years. The
Cadbury factoiy still _6 (make) chocolate in the United Kingdom, and the chocolate is eaten all
over the world. Every year, thousands of visitors go to the factory to see how chocolate is made.
答案：1. ________ 2. ________3. ________4.________ 5.________ 6.________
，水平飞行速度为
，追击一辆速度
同向行驶的汽车，欲使从飞机上投下的炸弹击中汽车，飞机应在距汽车水平距离______处投弹。（
）