刮扳机在哪些情况下应采取防滑措施？
参考答案：
向上输送坡度不大于35度，向下时不大于25度，在工作面不应大于10度，超过时要采取防滑措施。
The enrollments at College X and College Y both grew by 8 percent from 1980 to 1985. If the enrollment at College X grew by 800 and the enrollment at College Y grew by 840, the enrollment at College Y was how much greater than the enrollment at College X in 1985
A．400
B．460
C．500
D．540
E．(E) 580
