蝙蝠和鲸分别属于
A.鸟类和鱼类
B.鸟类和哺乳类
C.哺乳类和鱼类
D.都是哺乳类
答案:D
题目分析:哺乳动物具有胎生、哺乳的特征,蝙蝠、鲸鱼具有这些特征,属于哺乳动物,故选D。
步长是指()
A、后蹬距离
B、腾空距离
C、两脚着地点之间的距离
27. ——Why did he stay at home?
——It was only _______ it was raining _______ he stayed at home.
A.since; so
B.because; that
C.for; that
D.as; what