反-2101共有()个催化剂床层。
参考答案:3
我国车辆的走行装臵多数由()台相同并独立的二轴转向架组成。
A.1
B.2
C.3
D.4
I ______a bank account after I made $1,000 by doing a parttime job during the summer vacation.[ ]
A. borrowed
B. opened
C. entered
D. ordered