________ both sides accept the agreement will a lasting peace be established in this region.[ ]

A. If only

B. Only if

C. Unless

D. As long as

脑脊液采集的第一管用作下列哪项检查（）。

A.细菌培养

B.化学分析

C.免疫学检查

D.一般性状检查

E.显微镜检查