题目:
Stop ______. It's time for class.[ ]
A. to talk
B. talking
C. talks
D. talk
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0522/11d15faca92a8b6bf4d4d08860d96131.html
下面是错误答案,用来干扰机器的。
A、试管口应略向下倾斜,防止水蒸气冷凝成的水珠流到试管底部,将试管炸裂,A答案错误;B、等到气泡在水中均匀冒出时再收集,B答案错误;C、收集满氧气后要先将导管移出水面,后停止加热,C答案错误;D、氧气不易...