()项可能是造成油泵不喷油现象的原因之一。
A、油量不足
B、油中混有异物
C、压力表损坏
D、压力设备设定不当
参考答案:A
____, the more expensive the camera, the better its quality.
A.General speaking
B.Speaking general
C.Generally speaking
D.Speaking generally
肝血窦的哪些结构与物质交换有关?