下面对火灾种类的叙述，（）是不对的。
A.A类为固体物质的火灾
B.B类为液体物质的火灾
C.C类为气体火灾
D.D类为电气火灾
参考答案：D
人类染色体可分____________和________两种。
Not all the students would rather _______ computer games than _______.
A．play, study
B．playing, studying
C．to play, to study
D．playing, study
