— Has ______ problem been solved?    

— Not yet. We're trying to think of ______ way out, but it's quite difficult to find one. [ ]

A. a; the    

B. the; a    

C. a; a      

D. the; the

药典规定“按干燥品（或无水物，或无溶剂）计算”是指（）

A.取经干燥的供试品进行试验

B.取除去溶剂的供试品进行试验

C.取经过干燥失重的供试品进行试验

D.取供试品的无水物进行试验

E.取未经干燥的供试品进行试验，再根据测得的干燥失重在计算时从取样量中的扣除