In the passage of Unit 2., although global warming is a popular topic in science classes in most middle and high schools, there is ( ) understanding of the greenhouse effect.
A.much B.a better C.little D.a little正确答案C
In the passage of Unit 2., although global warming is a popular topic in science classes in most middle and high schools, there is ( ) understanding of the greenhouse effect.
A.much B.a better C.little D.a little正确答案C
