单项选择题
Mainly east 3 or 4 partly cloudy to overcast occasional...
单项选择题Mainly east 3 or 4 partly cloudy to overcast occasional rain（）slowly south moderate or good.
A.spreading B.proceeding C.bounding for D.going to
密封填料如果使用代用品填入，会造成水泵故障。
判断题密封填料如果使用代用品填入，会造成水泵故障。
开关电源如何散热？
问答题开关电源如何散热？
