(1)原式=1+23+2-3
=3+3;
(2)原式=52+4222-4
=92-4
=12.
The meeting ______ tomorrow afternoon is about _______ rid of pollution.
A.held, to get
B.to be held; getting
C.to hold; to get
D.being held; getting
膨胀阀内制冷剂流通应正常,无阻塞现象,热力膨胀阀出口一侧应()。
A.结露
B.结霜
C.结露或结霜
D.与入口侧温度相同