Women usually like to get together to talk about daily affairs _____ clothing and food.[ ]

_____to nuclear radiation, even for a short time , may produce variants(变异体) of genes in human bodies.

. It was an agreement ________ could not be changed.

. —He must be a true friend, isn’t he —Of course he is. He seldom ____________ a badword about others.

______ about his own safety, though he was ingreat danger himself.