Researchers show there is a clear warming trend of about 0.5 degrees centigrade from 1900 which they （ ）the greenhouse effect.
A.contribute to B.attribute to C.subscribe to D.apply to正确答案B
Researchers show there is a clear warming trend of about 0.5 degrees centigrade from 1900 which they （ ）the greenhouse effect.
A.contribute to B.attribute to C.subscribe to D.apply to正确答案B
