通过电风扇的电流大约是400mA,等于_________A,等于________μA。
0.4;4×105
It's not easy _____ a house for my pets.[ ]
A. to keep
B. keeping
C. to make
D. making
脱硫塔压力高低直接影响气液分离和液面,压力()分离效果好。