Mr. White has been --------(缺席的)from work for days, so he knows nothing about our new plan.
第1题:
A、are…being
B、is…being
C、has…been
D、have…been
第2题:
A.knows...how
B.know...how
C.knows...what
D.knew...what
第3题:
第4题:
A、is, to translate
B、has, to translate
C、is, in translating
D、has, in translating
第5题:
[A] on
[B] from
[C] at
[D] about
第6题:
He-Ne 激光属于四能级系统产生的激光