【分析】根据一次函数图象经过的象限找出k、b的正负，再结合根的判别式即可得出△＞0，由此即可得出结论．
下列命题中，假命题是（ ）
某校七年级1班50名同学在“森林草原防灭火”知识竞赛中的成绩如表所示：
成绩 | 60 | 70 | 80 | 90 | 100 |
人数 | 3 | 9 | 13 | 16 | 9 |
则这个班学生成绩的众数、中位数分别是（ ）
My aunt wanted to take a taxi so that she ________ get to the airport on time.
He ______ sleep,although he tried to. One cup of coffee in the late afternoon caused him tostay awake almost all night.
—What a lovely present!Who sent it? __________it be your brother?
—It __________be my brother. He doesn't know today is my birthday.
—Excuse me, are the glasses Mike’s?
—No, they __________be Mike’s. He doesn’t wear glasses.
— Is that man your friend Tom?
—That man ________ be him,because he has gone to Canada.
—Sam, ________ I join you in the community service?
—Of course you can.
