The company had to______a number of workers because of the drop in sales.

A．see off

B．take off

C．cut off

D．lay off

通过抑制细胞免疫而发病的传染病是（）

A.乙型肝炎

B.艾滋病

C.麻疹

D.肺结核

E.流行性出血热