Not until all the fish died in the river ____ how serious the pollution was. [ ]

Shall I give you a lift as you live so far away—Thank you. _____________.

We should do more such exercises in the future，I think，_____ thosewe did yesterday

Look! They’re the old teaching building— It’s unwise to do that

34It took the early settlers more than 150 years to build up___________is now a modern city