甲说：计算机估损系统可以自动扣减重叠工时；乙说：在输入VIN码后，估损系统能够解出车

____ printed, this science fiction will be popular among the students.

A．Before

B．Unless

C．When

D．Once

—___________ bag is this?

—It's Simon's. [ ]

A. Whose

B. Who

C. Who's

D. Which

锁斗系统故障，某个阀门动作不到位的原因可能是（）。

A.阀门轴承折断

B.仪表逻辑系统掉电

C.现场电磁阀失灵

D.有大块渣或异物卡住

神经系统疾病定性诊断应注意哪些问题？