Unless you see a dentist, your tooth will be very painful.（保持原意）

Although she is more than forty, she looks very young.（保持原意）

He is well-built, rather short and bald.（劃線部分提問）

He doesn't speak French. He doesn't speak German, either.（合并句子）

The government allows higher bus fares.（改為被動語態(tài)）

The boys became interested in science after they had visited the Space Museum.（劃線部分提問）

Sometimes the pollution is thick. It is like a blanket over a city.（合并句子）

They have already visited the Ocean Park.（改為一般疑問句）

We use air conditioners to keep rooms cool in summer.（保持原句意思）

He told his story to a reporter from a Chicago newspaper.（改成一般疑問句）