①马克思 ②斯大林 ③恩格斯 ④列宁
A:①②
B:③④
C:①③
D:②④
用反证法证明命题“若abc=0,则a,b,c中至少有一个为0”时,假设正确的是( )
下面是两条重要的交通路线图,它们开通的共同作用是( )
阅读下面的一段话,判断正误。
Hi! I'm John. Come here, my friends! Look at my dog. It has two big eyes. It's very cute. This is my cat, Mimi. It's fat. It's two years old. I have six fish. Oh! Mimi likes(喜欢) my fish. I have a bird, Polly. It's beautiful!