The kidney transplant operation was _____ complicated, so the operating team had to take special care to ensure its success.

It is very expensive to （ ） the fashion.

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

（ ） has already been pointed out before, English grammar is not a set of dead rules.

We don’t doubt _____ he can do a good job， concerning his experience.

Mr. Jones, _____ life was once very hard, is now very successful in his business.

I cannot tell the_____difference between the twins.

The film （ ） him of what he had seen in China.

Thank you for your letter of May 6, in which you _____ about the bicycles of Model 897.

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

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

（ ） he often forgot their wedding anniversary greatly annoyed his wife.