在井下绝对禁止打开矿灯电池盒或打开灯头。若强行打开，势必损坏闭锁和矿灯，而且会产生火花，会引起瓦斯爆炸等重大事故。（）
参考答案：对
—I hear Jane has gone to the Holy Island for her holiday.
—Oh, how nice! Do you know when she______________?
A． was leaving
B． had left
C． has left
D． left
管顶标高
