问题
单项选择题
多项式M=4x2-9x+4a，N=3x2-9x+4a，当x为任意一个有理数时，下列结论正确的是（）。
A．M的值必小于N的值
B．M的值必不大于N的值
C．M的值必大于N的值
D．M的值必不小于N的值
答案
参考答案：D
解析：
M-N=(4x2-9x+4a)-(3x2-9x+4a)=x2≥0，故M＞N或M=N，选D。
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多项式M=4x2-9x+4a，N=3x2-9x+4a，当x为任意一个有理数时，下列结论正确的是（）。
A．M的值必小于N的值
B．M的值必不大于N的值
C．M的值必大于N的值
D．M的值必不小于N的值
参考答案：D
解析：
M-N=(4x2-9x+4a)-(3x2-9x+4a)=x2≥0，故M＞N或M=N，选D。
| 选词填空，并注意词形变化。 | |
I am writing to 1_____ that I am 2_____ building a new zoo in our town. Zoos are 3_____ places for animals to live. I 4_____ a lot of zoos in my life, and I have never seen one I like or one that was 5_____ for animals to live in. Just last week, I visited a zoo and couldn't 6_____ what I saw. The animals were kept in 7_____ cages and could 8_____ move at all. And they were only 9_____ food once a day. Is this a good way for animals 10_____? I don't think so! Sincerely, Disgusted |