下列器官能吞噬衰老的白细胞、红细胞和血小板的是（）.
A、肝
B、脾
C、肾
参考答案：B
长江中下游湿地破坏严重，主要是因为该地区[ ]
A．用水增多，地表水减少
B．城市化进程加快，占用大量湿地
C．围湖造田，泥沙淤积
D．大片湿地改为鱼塘
He checked out his composition again and again to make sure that no important points had been_______.[ ]
A．found out
B．run out
C．made out
D．left out
