题目

    The other day, I was thinking about the phrase It's a dog's life. According to my dictionary, this means life is hard and unpleasant, but that definition is surely obsolete. A dog's life these days, at least in my house, is extremely comfortable.     This is by no means the only phrase in the English language that suggests a dog's life is a sad one. When we become less successful than we were in the past, we go to the dogs;when we do something very badly, we make a dog's breakfast of it; if we feel really bad,we're as sick as a dog. Unattractive or unpleasant people are cons关于函数y=﹣2x+1，下列结论正确的是（　　）A. 图象必经过点（﹣2，1） B. 图象经过第一、二、三象限C. 当x＞时，y＜0 D. y随x的增大而增大