人体淋巴结内存在着大量的有吞噬作用的细胞,这些细胞能吞噬侵入人体内的病原体。这种免疫属于()
A.非特异性免疫
B.特异性免疫
C.自然免疫
D.人工免疫
参考答案:A
-I hear that you will be on travel again.
-Yeah.My boss __________ for me to discuss business details with someone from another company.[ ]
A.asked
B.arranged
C.sent
D.called
下面哪个B737-600传感器不会导致组件跳开(PACKTRIP)灯亮()。
A.压气机出口过热电门390°F
B.涡轮进口过热电门210°F
C.组件出口过热电门250°F
D.管道过热电门190°F