运输线路中的内河航道有（）个等级。
A.4
B.5
C.6
D.7
参考答案：D
The woman sold the eggs _____ seven dollars and they were sold ____ half price.
A．with; at
B．for; at
C．at; in
D．by; on
right away
A.跑掉 B立刻，马上 C.稍后
