梅钢电镀锡机组的出口段速度为620米/分。
参考答案:错
My dictionary ________ . I have looked for it everywhere but still ______ it .
A.has lost ; do not find
B.is missing ; do not find
C.has lost ; have not found
D.is missing ; have not found
消弧线圈的作用是什么?