绞锁
参考答案：绞锁：开闭口过程中遇到阻碍，而不能继续开口或闭口的现象。
—Is that your marker?
—________.[ ]
A. Yes, that is
B. Yes, it's
C. No, it isn't
D. No, that isn't
打磨机研磨光洁度与砂纸粗细有关，与振动幅度大小无关。
