作图示构件的受力图
参考答案:
Passage Three
The peanut is ______.
A.of little nutritional value
B.difficult to grow
C.a plant that exhausts the soil
D.a source of protein
风机转子在安装前对转子要求是:风机转子在安装前必须做()平衡试验,在自由状态下转子动平衡水平振动,双振动幅要小于()㎜。