I don't have a partner to practice French _____. [ ]
A. by
B. with
C. on
D. to
答案:B
Five million, five hundred and fifteen thousand, one hundred and fifty-one is __________.[ ]
A. 5,515,151
B. 5,151,151
C. 5,151,515
D. 5,551,155
为保证电力系统正常运行状态及承受第Ⅰ类大扰动时的安全要求,应由()等,组成保证电力系统安全稳定的第一道防线。
A.一次系统设施
B.汽轮机快速控制汽门
C.继电保护
D.安全稳定预防性控制