题目

He goes to school by bus, but he walks ______after school. A. to home  B. home       C. his home  D. the home 答案：B 水绵、蓝藻、黑藻全部 [　　] A． 是真核生物 B． 含有叶绿体 C． 是自养生物 D． 能有丝分裂