语法结构1. There have been many _ in their marriage but they still love each other. A. right and wrong B. back and forth C. ups and downs D. right and left解析：正确答案为C。many修饰可数名词的复数形式，选项中只有C符合，“ups and downs”为固定词组，意为“起落、沉浮、盛衰”。2. The officials in the _ at London airport were very polite. A. Custom B. Customs C. custom D. customs解析：正确答案为B。“the Customs”特指“海关”。3. His words are _ but the meaning is deep. A. few B. a few C. little D. a little解析：正确答案为A。“word
