古代世界上最长的运河是 [ ]
A．巴拿马运河
B．京杭运河
C．隋朝大运河
D．苏伊士运河
答案：B
Tim's mum is worried ______ her son's eyesight as he plays online games too much.[ ]
A. for
B. about
C. with
D. of
工作范围
