《Pollution has caused too many problems》SectionD PPT-302edu教育资源网

It _____ (be) beautiful in the past. Kangkang _______ (go) there two years ago.

The flowers and grass ___________ (go). Everything _____________ (change).

Mrs. Zhou ____________ (be) like this since last week. She ______________ (not see) a doctor yet.

was

went

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.

获取资源