Fred entered without knocking and, very out of breath, sank _______ a chair. 
| A．on | B．off | C．into | D．to |
His mother was born in Green, and Greek was her native language, ___.
| A．so it was with his father | B．so did his father | C．so was his father | D．so his father was |
While reading, you'd better make a mark ___ you have any questions.
| A．on which | B．at where | C．the place where | D．where |
Don't keep your mouth ___ if you want to improve your spoken English.
| A．shut | B．shutting | C．shutted | D．to shut |
My classmates, Li Ming, was highly praised for ___ a good deed.
| A．doing | B．have done | C．having done | D．being done |
There are many pine trees on ___ of the street.
| A．every side | B．neither side | C．both side | D．either side |