题目

．若，则必有    A．、异号B．、同号    C．、中至少有一个为0D．、异号或、中至少有一个为0  答案：D 解析:略 These photographs will show you ________. A. what does our village look like　　　　 B. what our village looks like C. how does our village look like　　　　  D. how our village looks like