We all know laws to discourage the use of plastic bags _______ in many parts of the world.
I have finished translating a large part of the book, but the rest ___ more difficult.
After the new type of rice was introduced, the farmers produced _______ rice this year as last year.
The chairman thought _____ necessary to invite Professor Smith to speak at the meeting.
_____ we were worried about was _______ they could manage to control the pollution.
The manager of the supermarket was so impatient and even rude! I will never go shopping in that supermarket again and __________________.