The police were trying to _____ where the drug dealers were _____ it suddenly dawned upon them

that they might be hidden somewhere 10 miles within the border between the two countries. [ ]

A. come out; when  

B. make out; while  

C. figure out; when  

D. think out; since

图表示根细胞液中三种物质随氧分压变化的曲线，下列说法正确的是（）

A．都是通过主动运输从土壤中吸收来的

B．浓度变化不会影响到细胞吸水

C．糖的降低与N、P的增加没有关系

D．细胞膜上运输K比运输N的载体多