企业外购材料时，通常经过以下哪几个步骤（）A.请购处理 B.采购订货 C.采购验收

The teacher said, "My son had the same experience as the little boy."

The teacher said that his son had __ the same experience as the little boy. [ ]

A. been      

B. have

C. had      

D. done

---Hobo，what are you doing?  ---I’m       as a Monkey King．

A．celebrating

B．dressing up

C．1ooking

D．excited

若一个三角形三个内角度数的比为2︰7︰4，那么这个三角形是  [ ]

A.直角三角形

B.锐角三角形

C.钝角三角形

D.等边三角形

下列（）是稳性过大的征兆。

A．船舶摇摆剧烈，恢复较快

B．油水使用左右不均，产生较大横倾

C．风浪较小，横倾较大且恢复较慢

D．以上都是

如何对新建或改造发电机的参数进行管理？