________ the classroom, the teacher found all the parents already______ there.
| A．Entered; seated | B．Entering; seating |
| C．Entered; seating | D．Entering; seated |
Rather than ______ to a secure life, the young man prefers wandering about in big cities, enjoying himself.
| A．settle down | B．to settle down | C．settling down | D．settled down |
Quarrels often _______ between the wife and husband but they both wish to take measures to prevent them ______ happily.
| A．break out; from living | B．break up; to live |
| C．happen; to live | D．take place; from living |
_______ you have masses of work to do, you don’t have to help me with the housework.
| A．So that | B．Now that | C．If that | D．in that |
Believe in yourself and work hard and ______ your final goal will be achieved.
| A．therefore | B．so | C．thus | D．by this way |
It still puzzles today’s scientists ______ some mammals produce their young ______ others lay eggs to produce their offspring( 后代)
| A．that; while | B．why; while | C．how; when | D．what; as |