液化石油气泵前过漏器中的滤网眼通过面积必须大于管径的()。
A.1倍
B.1.5~2倍
C.3倍
D.4倍
参考答案:B
We had sat down at the table, when the phone rang.
A.possibly
B.hardly
C.virtually
D.politely
以下4组用户定义标识符中,全部合法的一组是( )。
A._main enclude sin
B.If -max turbo
C.txt REAL 3COM
D.int k_2 _001