The maths problems are too hard, only ______ people can work them out.

Jim is shy and he always avoid _______ in front of the class.

Mr. Green stood up in defence of the16-year old boy，_________that he was not the one ____________.

The man got to New York in 1998,_______ some time later, he became a famous computer engineer.

It’s dangerous to swim here. Look at the sign.–Oh, I it. Thank you.