起始进近航段采用直线航线时,保护区的副区在主区两侧,宽度各为总宽度的:().
A.1/2
B.1/3
C.1/4
D.1/8
参考答案:C
It ________ quite correct that happiness comes from thinking about things in a positive way. [ ]
A. has turned out
B. has been turned out
C. is turning out
D. is turned out
青蛙的变态发育大约经历多少天[ ]
A.30多天
B.40多天
C.50多天
D.60多天