管道运输的缺点是不够灵活，承运的货物比较单一，不能改变路线等。( )
参考答案：对
用所给单词的适当形式填空。
1. Miss Gao told us how to improve our _____ (speak).
2. Mr Smith is going to start _____ (teach) in China.
3. If you want _____ (study) English well, you should practice _____ (speak) it every day.
4. My job is _____ (make) the city much cleaner.
5. We _____ (make) our resolution yesterday.
比重计法土粒粒径计算系数k值与（）有关。
A.土粒比重
B.土粒沉降时间
C.悬液温度
D.悬液浓度
