题目

求y=的值域. 答案：解：y= =.令M=x2+2x+3=(x+1)2+2,x∈R,∴M≥2,∴0＜≤,∴-≤＜0,-≤2+＜2,∴y∈[-,2]是所求函数值域.Just Help the Next PersonThe only highway to go to work that we had to drive was closed down due to an accident on the bridge. A truck had hit the bridge and made it 36 for any traffic to go over it. So in order to get to 37 I had to go a number of miles out of my way. Not being that 38 with this road and not knowing 39 all the pot holes in the road were, I topped a hill and right in my path was a big pot hole. I felt and heard the familiar sound of a flat tire. I 40 as far to the right as possible and stopped. I tried several times to change the tire, but 41 .There I sat out in the country and no way to 42 with anybody. Just then, I looked in my rear view mirror and a 43 was pulling out of a pasture behind me. I was 44 and scared at the same time. I was struggling to get the 45 out when this man in the pickup pulled in behind me. He got out to introduce himself and 46 to help me. When he got the spare out we discovered that the spare is also 47 . He told me he would take the tire and have it 48 and call my husband. We got the tire fixed 49 he took me back to my car. My husband was there 50 us when we got back. The kind stranger stayed there and helped my husband 51 the tire. After they finished we 52 thanked him and offered to pay him for his 53 . I will never forget his words, " your thanks is 54 enough pay and I just hope if this ever happens to my wife or daughter someone will be so 55 as to help them." 小题1:A．busyB．narrowC．fearfulD．unsafe小题2:A．schoolB．cityC．workD．shop小题3:A．satisfiedB．involvedC．identifiedD．familiar小题4:A．whereB．whatC．whenD．which小题5:A．placedB．rodeC．pulledD．managed小题6:A．failedB．abandonedC．passedD．dropped小题7:A．catch upB．get in touchC．have to doD．put up小题8:A．truckB．pickupC．carD．bike小题9:A．excitedB．relievedC．determinedD．nervous小题10:A．carB．wheelC．spareD．trunk小题11:A．refusedB．offeredC．pretendedD．promised小题12:A．flatB．damagedC．invisibleD．lost小题13:A．soldB．paintedC．packedD．fixed小题14:A．butB．soC．andD．though小题15:A．listening toB．worrying aboutC．waiting onD．searching for小题16:A．breakB．changeC．cleanD．repair小题17:A．bothB．allC．neitherD．everyone小题18:A．imaginationB．troubleC．diligenceD．patience小题19:A．more thanB．less thanC．rather thanD．better than小题20:A．politeB．activeC．kindD．wise