第1题:
第2题:
第3题:
A、has taken
B、has been taking
C、is taken
D、has been taken
第4题:
Mary is not here. She () to Paris.
第5题:
第6题:
第7题:
第8题:
After a fire has been extinguished in a closed space, personnel may safely enter the space when
A.smoke density has been decreased sufficiently to see the bulkhead opposite the compartment's entrance
B.a lifeline and explosion proof flash light are used
C.all smoke and toxic fumes are removed and an adequate oxygen supply is present
D.overhaul has been completed to remove any possible source of re-ignition
第9题:
第10题:
The technician has suspicions that a browser has been hijacked. Which of the following should the technician look for in this situation?()