Tom talked with a friend of _______ on the Internet for a long time yesterday.

I admire my English teacher. I can remember very few occasions _____ she stoppedworking because of ill health.

The problem is difficult _______.[ ]

She has worked in this factory ______ she came here in 2010.

Though iphone7 will come out this coming September, it’s impossible for me to buy one for my father is ______ imported (进口的) goods.