问题
单项选择题
止回阀由阀体、阀座、（）、阀盘、密封圈等组成。
A、阀盖
B、填料
C、阀杆
D、旋塞
答案
参考答案：A
搜题请搜索小程序“爱下问搜题”
止回阀由阀体、阀座、（）、阀盘、密封圈等组成。
A、阀盖
B、填料
C、阀杆
D、旋塞
参考答案：A
| 用括号里所给单词的适当形式填空。 |
| 1. There _____ (be) a ruler and two pencils in the pencil-case. 2. I have five _____ (photo) of my friend at home. 3. That is _____ (Daming) mother. Let's go and say"Hello"to her. 4. Mike doesn't like _____ (play) football, but he likes swimming. 5. The women are _____ (secretary) at the factories |