中冷器的芯子用管子制成，发动机的（）在其中循环流动。
A.机油
B.冷却水
C.排气
D.进气
参考答案：B
Only when the final examination was coming ________ he had quite a lot to do. [ ]
A. he realized
B. he had realized
C. did he realize
D. had he realized
消化道传播的传染病包括：（）
A.登革热
B.伤寒
C.麻疹
D.白喉
E.乙型脑炎
