当APU起动时,若APU转速达到30%前,主、次燃油路情况如何()
A.同时供油
B.都不供油
C.主燃油路供油
D.次燃油路供油
参考答案:C
Whenever I go to Beijing, ____ is quite frequent, I will go to visit the Great Wall.
A.where
B.which
C.as it
D.It
消化道纤维内窥镜检查发生感染的无关因素是
A.病原体的种类B.病原体的毒力C.内窥镜消毒情况D.免疫功能E.操作者的技巧