甲,乙两人加工—批零件,已知甲单独加工要10小时完成,而甲和乙工作效率之比为8:5,现两人共同做了2小时之后,还剩下270个零件未加工,则这批零件共有()个.
A. 360
B. 400
C. 480
D. 540
E. 500
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古时有士兵1 800人守城,准备了120日的粮食,若增兵600人,而每人每日粮食定量比原来减少了1/3,则所准备粮食可以支持()日.
A. 120
B. 125
C. 130
D. 135
E. 140
Nobody had thought of installing enough lifeboats to accommodate all the passengers and crew in the event of an emergency.
A. Y
B. N
C. NG
【B8】
A. pulled
B. imposed
C. drawn
D. exerted
【B6】
A. opposing
B. complementing
C. confusing
D. existing