1、本网站免费注册后即可以下载，点击开通VIP会员可无限免费下载！
2、资料一般为word或PPT文档。建议使用IE9以上浏览器或360、谷歌、火狐浏览器浏览本站。
3、有任何下载问题，请联系微信客服。
扫描下方二维码，添加微信客服
have gone
has changed
has been
hasn’t seen
Simple past 强调过去
Present perfect 强调现在
They are caused
by pollution.
There are many kinds of pollution around us,
air pollution
light pollution
litter
water pollution
soil pollution
noise pollution
Read through Sections A-C and fill in the blanks with the correct words.
Grammar
What _________________ (happen) here?
There ______ (be) lots of flowers and grass.
I _____ (go) there two years ago.
The flowers and grass ____________ (go)!
I have ______ (be) like this since last week.
been
were
has happened
have gone
went
Simple Past ＆Present Perfect
…does great _______ to people’s hearing.
…many teenagers in America can hear no ______ than 65-year-old people do, …