I remember ______ to Beijing when I was a child.
A. to take
B. taking
C. to be taken
D. being taken
查看答案
We only planned ______ the play for an hour, but in the end, we stayed for three hours.
A. watch
B. watches
C. to watch
D. watched
磨料磨损的机理包括（）
A. 微量切削
B. 疲劳破坏
C. 压痕破坏
D. 断裂
磨料磨损的过程包括（）
A. 金属表面产生局部塑性变形
B. 折断
C. 表面被划伤
D. 磨粒嵌入金属表面，切割金属表面
根据磨损结果，磨损可以分为（）
A. 点蚀磨损
B. 胶合磨损
C. 擦伤磨损
D. 微动磨损
微信支付 
支付宝支付