The collision bulkhead shall be of ______.
A.water-tight
B.air-tight
C.fire-tight
D.oil-tight
第1题:
Shall ______ turn left at the crossing?
A、I
B、you
C、they
D、us
第2题:
A. is
B. is going
C. will
D. shall
第3题:
第4题:
A、should
B、ought
C、must
D、shall
第5题:
A. Crosstalk
B. Broadcast storm
C. Duplex mismatch
D. Collision
第6题: