______ , Martin can reach the branch of that tall tree at the gate.

（ ） when she started complaining.

I love thinking of new designs. It keeps my mind clear and active and fills my retired life with （ ）.

（ ） born in Chicago, the author is most famous for his stories about New York City.

（ ） relatively costly, the engine is highly efficient and needs servicing infrequently.

It is （ ） impossible to work with this noise around.

_____, the professor is still trying to learn a new language.

My advice is that she （ ） to apologize to him.

Mr. Green said his clients _____ our samples by the end of last month.

The two companies decided to （ ） on a project concerning animal cloning.

If you get into difficulties, don’t hesitate to （ ） help.

Let’s read the novel together, （ ）？