某同学在操场上向北走40m，接着又向南走30m，他的合位移大小是 A．10m B

填空

1. There were many people on the bus，it's c_____ .

2. The car is too e_____ I can't buy it.

3. It was s_____ and hot every day.

4. We had a wonderful dinner at this restaurant. The food was d______ .

5. I had a good summer v_____ in Shanghai with parents.

有共有人的房地产拍卖，须有共有人的书面同意转让意见。共有人享有优先购买权。( )

以上可治疗老年痴呆的是

A．氯琥珀胆碱
B．吗啡
C．硝酸毛果芸香碱
D．加兰他敏
E．硫酸阿托品

木材在建筑工程中，主要用于建筑装饰装修工程。

打扫（）保护罩附近和上面堆积的煤粉，保证保护罩上的通气孔不堵塞。

A.减速机

B.液力耦合器

C.电机

D.支架