Mary often forgets ________ her English book.

It’s his brother __________ never been to Australia. You’d better take him with you.

What is your sister going to be ________ she growsup?–She is going to be an engineer.A．before

33．—- Hi, Vera, have you checked the account yet?—- Certainly, I ______ it five times even though you told me to do it twice

What impressed the visitors deeply was ______ the workers made with their hands