一般每次垃圾推铺厚度达到（）时，进行压实。 A.30～60cm B.50～100cm

膜剂制备中，可作脱膜剂的是

A．甘油
B．豆磷脂
C．碳酸钙
D．山梨醇
E．液状石蜡

Read and choose. (根据句子内容选出答案)

1. It's an animal. It likes to catch the mouse. It is a ____.[ ]

A. dog            

B. cat            

C. tiger

2. It's a kind of colours. The tree always have it. It is _____.[ ]

A. pink            

B. white          

C. green

3. It's a room. When you get tired you can sleep there. It is a _____.[ ]

A. bathroom          

B. kitchen            

C. bedroom

4. It's a kind of food. The rabbit likes it very much. It is a _____.[ ]

A. carrot            

B. beef            

C. bread

5. Winter is very cold. We can wear _____.[ ]

A. shirt            

B. sweater                

C. shorts

设a，b，c分别是△ABC角A，B，C所对的边，sin²A+sin²B-sinAsinB=sin²C，且满足ab=4，则△ABC的面积为______．

可引起急性胃炎的因素有（）。

A.药物

B.幽门螺杆菌

C.应激

D.病毒

E.乙醇

破碎机转动系统主要包括哪些部件？