-----Have you finished your composition already, Jack? ----Yes, I _____ it within half an hour.
| A．have finished | B．finish | C．finished | D．had finished |
It puzzles the scientists _____ some mammals produce their young _____ others lay eggs．
| A．that; while | B．what; while | C．that; as | D．what; as |
Many Internet users make _____ most of the half-price promotion and it is _____ good opportunity for online shopkeepers to get their names known．
| A．a; the | B．/; the | C．the; / | D．the; a |
After she made herself up, she herself in the mirror.
| A．admired | B．enjoyed | C．found | D．Showed |
at the airport, he was arrested by the police.
| A．When arrived | B．As arrived |
| C．At arriving | D．On his arrival |
In order to find better job, he decided to study second foreign language.
| A．the; a | B．a; a | C．the; the | D．a; the |