15（）
A. and
B. but
C. or
D. so
18（）
A. Why
B. How
C. When
D. Where
10（）
A. disappointment
B. joy
C. sorrow
D. surprise
What is the advantage for passengers who travel in a group of ten or more（）
A. They may buy the tickets direct from the on-board staff.
B. They will not pay for booking service.
C. They may get a discount.
D. They can pay in cash.
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