-Where is the bookstore?  

-Take the elevator         the second floorand turn left. And the bookstore is_______

the furniture store and the drugstore.     [ ]

A. at; next to                  

B. at; between    

C. to; between                

D. to; next to

在循环泵前后管路之间应装一根带有（）的旁通管，以防止突然停泵时发生水击。

A.截止阀

B.安全阀

C.阻气排水阀

D.止回阀