[单项选择]The changes in the city will cost quite a lot, ______ they will save us money in the long run.
A. or
B. since
C. for
D. but

[单项选择]The changes in the city will cost us a lot of money, ______ they will save us money in the future. ( )
A. or
B. since
C. for
D. but

[填空题] As a physician who travels quite a lot, I spend a lot of time on planes listening for that dreaded “Is there a doctor on board ” announcement. I’’ve been (71) ________ only once —— for a woman who had merely fainted. But the (72) ________ made me quite curious about how (73) ________ this kind of thing happens I wondered what I would do if (74) ________ with a real midair medical emergency-with out access (75) ________ a hospital staff and the usual emergency equipment. So 76 the New England Journal of Medicine last week (77) ________ a study about in-flight medical events. I read it (78) ________ interest. The study estimated that there are a(n) (79) ________ of 30 in-flight medical emergencies on U.S. flights every day. Most of them are not (80) ________;fainting and dizziness are the most frequent complaints. (81) ________ 13% of them ——roughly four a day —— are serious enough to (82) ________ a pilot to change course. The most common of the serious emergencies (83) ______
A. A．soon
B．long
C．many
D．often