细胞膜常常被脂质溶剂和蛋白酶处理后溶解,由此可以推断,细胞膜的化学成分可能含有( ) ①磷脂 ②蛋白质 ③多糖 ④核酸 A.①② B.②③ C.②④ D.①④ 答案:A 由相似相溶原理和酶的专一性可知,细胞膜的化学成分有磷脂和蛋白质。选出句中错误并改正。( ) 1. Is careful. The bus is coming. A B C( ) 2. John, does your homework quickly! A B C( ) 3. Nancy, please not open the window. A B C( ) 4. Don't is late for school again. A B C( ) 5. Let's us play games together. A B C