闸阀的阀盘与阀座的密封面泄漏，一般是采用（）方法进行修理。
A、更换；
B、加垫片；
C、研磨；
D、防漏胶水。
参考答案：C
完成句子。
l. If your friend ______ (练习) speaking English every day, he'll learn it well.
2. It's one of the highest ______ (建筑物) in this city.
3. The young man ______ (为……而挣钱) his study.
4. Every morning Zhang Yong is ______ (最早) student in his class.
5. There is ______ (大量) rubbish information on the Internet.
常规窗帘盒宜伸出窗口两侧（）。
A、50~100
B、100~200
C、150~200
D、200~250
