David talked with a friend of ________ on the Internet for a long time yesterday.
— What do you think of the young lady? — She is hard-working. She ________ all her effort into her work before she got ill.
The cost of living in Chengdu is among the lowest in China, ________ the quality of life is probablyone of the highest.
— Do you have any plans for the winter holiday?— Since you are crazy about music, why not go to some ________ concerts?
________ Mary ________ Jack is listening to the report carefully, because they are both interested in it very much.
I don’t make ________ clear when and where the parents’ meeting will be held.