She wanted the fort of a large car and the low cost of a small one，so she bought a size in between the two .
A. for promise
B. as a promise
C. as promise
D. for a promise
网友回答
A. for promise
(答案→)B. as a promise
C. as promise
D. for a promise
解析：此题考查介词。for“(表示目的)为了；因为；至于，对于，适合于”；as“作为”，as a promise“作为折中”。句意：她想要大车的舒适，小车的价钱，因此作为折中买了一辆大小在两者之间的轿车。