GRE Text Completion: Fundamental 24 Sets-GRE填空基础24套 - _4VZX0EVDU1H54U2!

Some scientists speculate that children who wash frequently are more likely to become asthmatic than those who wash infrequently: that ____________, not the lack of it, is the problem. A. pollution B. dirtiness C. scour D. misbehavior E. cleanliness F. nutrition