通风机的个体特性曲线可以反映通风机()之间的关系。
A.风压
B.功率
C.效率
D.风量
参考答案:A, B, C, D
阅读短文,选择正确答案。
Amy, Chen Jie, John and Wu Yifan are good friends. John often plays football with Wu Yifan on Saturday.
Amy does her homework every day. Chen Jie likes watching TV. She stays at home on Sunday. They all read
books on Monday.
1. Amy, Chen Jie, John and ____________ are good friends.[ ]
A. Zhang Peng
B. Sarah
C. Wu Yifan
2. ____________ does her homework every day.[ ]
A. Amy
B. Chen Jie
C. John
3. Chen Jie likes ____________. [ ]
A. watching TV
B. playing football
C. doing homework
4. They ____________ on Monday.[ ]
A. play ping-pong
B. do homework
C. read books
采用()挡出钢一次渣。
A.挡渣球
B.挡渣锥
C.挡渣塞
D.挡渣棒