The group of research workers are said to ________ to the dangerous nuclear radiation while they carried out their rescue task.

A．be exposed

B．have been exposed

C．exposed

D．be exposing

晶状体先天异常不包括（）

A.晶状体形成异常

B.形态异常

C.透明度异常

D.屈光度异常

E.位置异常