TOEFL Reading: ETS-TOEFL阅读机经 - 65XPXHOC56G64386L$

According to paragraph 6, high job mobility rates may benefit an economy by A. making it more likely that the economic environment will change significantly B. encouraging employers to increase the sizes of their workforces C. making it more likely that jobs will be filled by people who are suited to them D. encouraging workers to improve their skills