已知抛物线y=ax2+bx+c（a＜0）经过点（-1，0），且满足4a+2b+c＞0．以下结论：①a+b＞0；②a+c＞0：③4ac-b2＜0；④
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如图所示：∵抛物线y=ax2+bx+c（a＜0）经过点（-1，0），且满足4a+2b+c＞0，
∴a-b+c=0，-
＞b 2a
，b2-4ac＞0，1 2
∴b＞0，则a+c＞0，a＞-b则a+b＞0，由b2-4ac＞0则4ac-b2＜0，
∵a＜0，
＞0，b2-4ac-b
∴
＜0，故此选项错误．b2-4ac-b a
故正确的有3个．
故选：C．
| 完形填空。 | |||
| A loving person lives in a loving world. A hostile (敌意的) person lives in a hostile world. Everyone you meet is your mirror. Mirrors have a very particular 1 . They reflect the image in front of them. Just as a 2 mirror works as the vehicle to reflection, 3 do all of the people in our lives. When we see something beautiful such as a flower garden, that garden 4 a reflection. When we love someone, it's a(n) 5 of loving ourselves. We have often heard things like "I love how I am when I'm with that person". That simply 6 into "I'm able to love me when I love that other person". 7 , when we meet someone new, we feel as though we "click". Sometimes it's as if we've 8 each other for a long time. That feeling can come from 9 similarities. Just as the "mirror" or other people can be a positive reflection, it is more likely that we'll 10 it when it has a negative connotation (内涵). 11 , it's easy to remember the times when we have met someone we're not particularly 12 about. We may have some criticism (批评) in our mind about the 13 . This is especially true when we get to know someone with whom we would rather spend 14 time. Often, when we 15 qualities in other people, ironically (讽刺地), it's usually the mirror that's 16 to us. At times we meet someone 17 and feel distant disconnected, or disgusted. 18 we don't want to believe it, and it's not easy or 19 to look further, It can be a great learning lesson to 20 what part of the person is being reflected in you. It's simply just another way to create more selfawareness. | |||
| ( )1. A. target ( )2. A. medical ( )3. A. so ( )4. A. focuses on ( )5. A. reward ( )6. A. grows ( )7. A. Obviously ( )8. A. known ( )19. A. creating ( )10. A. ignore ( )11. A. In brief ( )12. A. crazy ( )13. A. time ( )14. A. less ( )15. A. appreciate ( )16. A. shouting ( )17. A. new ( )18. A. If ( )19. A. terrible ( )20. A. figure out | B. style B. physical B. then B. applies to B. evaluation B. translates B. Strangely B. supported B. lacking B. keep B. In addition B. anxious B. mirror B. amazing B. dislike B. shining B. nervous B. Although B. noble B. take out | C. function C. chemical C. nor C. works with C. reflection C. enters C. Fortunately C. observed C. sharing C. take C. For example C. upset C. garden C. more C. describe C. speaking C. familiar C. Since C. reliable C. put out | D. color D. mental D. neither D. serves as D. example D. falls D. Frequently D. recognized D. comparing D. notice D. As usual D. concerned D. person D. valuable D. discover D. pointing D. friendly D. Once D. desirable D. give out |