13. — How do you keep fit?
— By having a healthy diet and _________ regularly.
| A．turning out | B．working out | C．giving out | D．going out |
___ the end of this new term we'll have graducated from middle school.
| A．In | B．By | C．At | D．On |
The mid-term exam is to be held ___ the end of this month.
| A．on | B．by | C．in | D．at |
I’ll be free ___ seven o’clock.
| A．after | B．on | C．in | D．at |
We offered him our congratulations ___ his passing the college entrance exams.
| A．at | B．on | C．for | D．of |
In the dark street, there wasn’t a single person ___ she could turn for help.
| A．that | B．who | C．from whom | D．to whom |