设,且存在,证明:.
参考答案:
[证] 因为
In our school _______ students are able to surf the Internet for useful information now. [ ]
A. hundred
B. hundred of
C. hundreds
D. hundreds of
在高速公路变更车道时,应提前开启转向灯,观察情况,确认安全后,驶入需要变更的车道。