实验研究设计的研究对象为_________
A．人B．物体C．动物或标本D．人或动物E．化合物
参考答案：C
______of time and energy has been spent in making theearthquake-stricken areas a permanent
museum to remindpeople how disastrous a natural disaster can be. [ ]
A. Iarge quantities
B. A great deal
C. A great many
D. A plenty
强制润滑风机的正常供油温度为（）。
A.15℃
B.20℃
C.30℃----40℃
