13.Four and half hours of discussion took us up to midnight,and break for cheese,chocolate and tea with sugar. a;a 。 the; the 。 不填;the 。 a;不填 。
29. The door _____ open, no matter how hard she pushed. shouldn’t 。 couldn’t 。 wouldn’t 。 mightn’t。
23. Try not to cough more than you can ___ since it may cause problems to your lungs. check 。 allow 。 stop 。 help。
7. We very early so we packed the night before.