说明理由
1.The fastest thing in space is light.Light travels ______ 300,000km per second.
A.at a speed of B.with the speed of
C.at a speed about D.with the speed about
2.Lucy is waiting _______ No.3 bus stop _______ her father.
A.for...for B.for ...at C.at...for D.at...at
请说明理由,