单项选择题

If two trains are 120 miles apart and are traveling toward each other at a constant rate of 30 mph and 40 mph，respectively，how far apart will they be exactly 1 hour before they meet？（）

A. 10 miles
B. 30 miles
C. 40 miles
D. 50 miles
E. 70 miles

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单项选择题

A time—study specialist has set the production rate for each worker on acerta in job at 22 units every 3 hours．At this rate what is the minimum number of workers that should be put on the job if at least 90 units are to be produced per hour？（）

A. 5
B. 8
C. 12
D. 13
E. 30

单项选择题

A basket contains a total of 30 apples and pears．If it contains times as many apples as pears，how many pears does it contain？（）

A. 9
B. 10
C. 12
D. 18
E. 20

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