计算：（1）cos60°-tan45°tan60°-2tan45°；（2）2co

用所给单词的正确形式填空。

小题1:The school needs help _________(teach) art.

小题2:She is thinking of _______(join) the _________(dance) club.

小题3:Tom, _________(not talk) in class!

小题4:Let the girl _______(go) to school early.

小题5:When it ________(rain), I take a bus to school.

小题6:It’s a ________(fun) time for breakfast.

小题7:Little Tommy ________(brush) his __________(tooth) every morning.

小题8:There are nine __________(hundred) students in the school now.

可按国际挂号函件寄递有()。（1分）

A.印刷品 

B.盲人读物 

C.包裹 

D.小包

在请求页式存储管理方案中，目前常用的替换策略有：(1)先进先出；(2)优先级法。( )

机动车上路行驶时，前排乘车人可不系安全带。

至       年底，三大改造基本完成，我国进入社会主义                   。