Chrome，
QQ浏览器
.
![北师大数学七下《1.3同底数幂的除法》[张老师]【市一等奖】优质课](http://imgshow.1ydt.com/img?url=%2F%2Fi0.hdslb.com%2Fbfs%2Farchive%2F7f1c1dce-18a17cfcdc3.jpeg%40672w_378h_1c_%21web-search-common-cover)
.