According _some studies half of the sevice jobs pay low wages.
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Let me more _to my next main point.
A. on
B. in
C. at
D. for
you'll get the right training and education first,which is really the best way.
A. 对
B. 错
100 years ago ,80% workers produced goods today only about 20% do.
A. 对
B. 错
With the development of science and teachnology more and more people are leaving longer and longer.
A. 对
B. 错