你在本实验中掌握了哪些测量流量、压强的方法?它们各自有什么特点?
流体流动综合实验中用差压变送器测量压差,请简述差压变送器工作原理?
1) Which do you prefer to keep in touch with your friends. QQ _________ WeChat?
A. and
B. but
C. or
D. so
-Which do you like better,apple_______ orange?-I don't like apple _______ orange. I like watermelon.
A. and; or
B. and;but
C. or;but
D. or;or