下列叙述正确的是
A. 胃溃疡发病以保护因素的增强为主；十二指肠溃疡发病则以攻击因素的增强为主
B. 胃溃疡发病以保护因素的增强为主；十二指肠溃疡发病则以攻击因素的减弱为主
C. 胃溃疡发病以保护因素的减弱为主；十二指肠溃疡发病则以保护因素的增强为主
D. 胃溃疡发病以保护因素的减弱为主；十二指肠溃疡发病则以攻击因素的减弱为主
E. 胃溃疡发病以保护因素的减弱为主；十二指肠溃疡发病则以攻击因素的增强为主
Poor as he was, he cared little about money reward.
A. 他生活贫穷，所以对金钱报酬有些计较。
B. 他虽然生活贫穷，但对金钱报酬从不关心。
C. 尽管他生活贫穷，但对金钱报酬很少计较。
D. 他因为生活差，所以对挣钱比较关注。
Never before _________ available for quick and easy acess in so many different fields of study.
A. so much free information were
B. has so much free information been
C. were so much free information
D. so much free information has been
Professor Green suggested ______ the date for the final examination.
A. to change
B. changing
C. change
D. changed
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