Though the professor tried his best to explain the difficult question, the students still looked _____.

It’s more expensive to live in the city than to live in the countryside.— _________. Living in the city brings people more convenience, though.

I visited many places including the History Museum last Saturday. When I _______ at the hotel, it was very late.

When his father started questioning his explanation, he had to ____ more details for his mistakes.

I _____ watch foreign movies in my spare time ，but I appreciate Chinese ones occasionally at home.