无法交付的行李，自行李到达的次日起，超过（）天仍无人领取，承运人可按照无法交付行李的有关规定处理。
A.30
B.90
C.60
D.45
参考答案：B
Hard _____ he tried, he failed to catch up with the first runner.
A．although
B．as
C．while
D．when
