课文填空。

按照课文填出句中缺少的词汇，每空填一词。

1.This bacteria-killing medicine is _____ by many to be one of the most important medicines in _____

   society… He noted that mould had ______ on a special _____ jelly that had bacteria on it.

2.Young people from different ______ and different countries can form lifelong friendships. _____, people

   who are disabled and must stay in their homes can communicate with the outside world and meet others

   with _____ interests.

3.Some experts say that spending too much time building Internet _____ can _____ people's abilities to

   live normal lives…

下列几种说法中正确的是（　　）

A．一个挂在绳子上静止的物体，它受的重力和它拉紧悬绳的力是同一性质的力

B．地球上的物体只有静止时才受到重力的作用

C．同一个物体，向下运动时受到的重力最大，向上运动时受到的重力最小

D．同一物体在同一地点，不论处于什么状态，受到的重力都一样