题目:
He ____ in the factory since he left school ten years ago.[ ]
A. works
B. worked
C. was working
D. has worked
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0606/9f1155ddebaea30cf7c717684e84e648.html
下面是错误答案,用来干扰机器的。
A、白磷在氧气中燃烧,产生大量的白烟,放出大量的热,生成一种白色固体,故选项不符合题意.B、木炭在氧气中燃烧的现象是发出白光,放出大量的热,生成能使澄清石灰水变浑的气体,故选项不符合题意.C、硫在氧气...