There is a railway (铁路) _____ the two cities. [ ]
A. on
B. under
C. between
D. beside
答案:C
正数a 的两个平方根的和是0[ ]
鸡传染性法氏囊病易感日龄为( )。
A.1~4日龄
B.3~6周龄
C.5~8日龄
D.2~15周龄
E.15日龄以上