Once new difficulties _____ in our study, we should learn to use our brains to solve them.
My parents don’t allow_____ time_____ nothing.
Mr Smith doesn’t believe that his daughter can work out the problem that easily,_____?
It is said that Tom hasn’t passed the driving test, but, ______ he is a little too young.
She_____ have gone to Shanghai for a visit. She has been discussing the papers with me for a whole day.
-----I’m taking my TOEFL examination next week. -----______!