He often helps the students __________ he thinks are notquick at their studies.
-----Is this the first time you______ Chengdu?-----No. But the first time I______ here, the city wasn’t so beautiful
Has the doctor _______ called for?
Mr Smith has a lot of business______. I know by______ that this man cannot be trusted.
We _______ on this project for four hours. Let’s have a rest.
This dictionary is_______ to my translation, but that one is________.