齿状线周围的直肠癌淋巴结转移的主要途径是（）
A.向下转移
B.向两侧转移
C.向腹股沟淋巴结转移
D.向上转移
E.以上都是
参考答案：A, B, D
Tom’s parents died when he was a child, so he was ______ by his relatives.
A．grown up
B．fed up
C．raised up
D．brought up
闸刀开关用字母（）表示。
A.FU
B.KN
C.SB
D.SA
