质量通病防治措施中要求，室外气温低于（）℃时，不宜进行外墙粉刷。
A、5
B、2
C、0
D、3
参考答案：A
在同一幅等高线图上[ ]
A、相邻两条等高线的数值差（即等高距）相等
B、闭合等高线的中心肯定是盆地
C、等高线越密集，表示地形越平坦
D、等高线越稀疏，表示地势起伏越大
The speaker _____ several other subjects in the course of his talk but mostly kept himself to the main topic.
A．held on
B．worked out
C．touched on
D．kept out of
