题目

（09马鞍山市质量检测）海带细胞中碘的浓度比海水中高出许多倍，其原因是     A．碘的穿透性特别强         B．碘能以主动运输方式进入细胞     C．海水中碘含量高           D．海带细胞膜是全透性的 答案：答案：B18、After the rebuilding our school is becoming  _______________． A． more and more beautiful                 B． more beautiful and beautiful C． beautiful and beautiful                    D． the more beautiful