1. [单选题]18．1 can _________ swim _________skate． Will you teach me how to swim and skate?
A. not only，but also
B. both，and
C. either，or
D. neither，nor
2. [单选题]28． Mike-s room isn’t tidy(整洁) because ________．
A. something is broken
B. he can-t find his watch
C. he is an English boy
D. his things are everywhere
3. [单选题]（2009?重庆）下列物质中不能在氧气里燃烧的是（ ）
A. 氮气
B. 焦炭
C. 硫黄
D. 天然气
