① 和
② 和
③CH4和CH3CH2CH3
④金刚石和石墨
⑤H、D、T
⑥乙醇(CH3CH2OH)和甲醛(CH3OCH3)
⑦臭氧(O3)和氧气(O2)
⑧ 和
⑨ 和
⑩CuSO4•5H2O与CuSO4•3H2O
—Alice, why didn’t you come yesterday?
—I ______, but I had an unexpected visitor.