52____.A.fearB.faceC.knowD.cause
52____.
A.fear
B.face
C.know
D.cause
相关考题：
According to the passage，some scientists believe that a dose of one rem of radiation continued over a period of generations would( ) A.raise the strontium 90 levels in the body but otherwise have little effect B.relieve the acute suffering of those afficted with arthritis of the spine without side effects C.have the effect of increasing by 1 percent the cases of serious genetic defects D.cause an additional 1 ，000 per million cases of cancer of the bone marrow or lymphatic system