题目

给出以下四个结论：①函数的对称中心是；②若不等式对任意的都成立，则；③已知点与点在直线两侧，则；④若函数的图象向右平移个单位后变为偶函数，则的最小值是，其中正确的结论是： . 答案：【答案】③④【解析】试题分析：①函数的对称中心是，因此不正确；②若不等式 对任意的 都成立,则 满足题意; ,可得 ,计算得出,因此的取值范围是,因此不正确；③已知点与点在直线两侧,则,则,正确；④若将函数的图象向右平移个单位化为，变为偶函数,则,当时, ,可得 的最小值是.其中正确的结论是③     "Grandma, Grandma, tell us a story!"  Four darling children sat by my feet, looking up at me expectantly.     Suddenly, we were interrupted clapping. "Terrific,"  the director said, stepping up the stage from the aisle(过道). "Except, could you kids face the audience a bit more?"      The kids shifted to face the empty seats, which would be filled in a few days for the church play."Perfect," the director said. "Now, Grandma, read to your grandchildren." A pang of sadness hit me. If only I could read to my real grandchild!     I had a granddaughter, but I'd never met her. Sixteen years earlier my son was involved in arelationship that ended badly. But out of it came a blessing: a baby girl named Lena. I hoped to be a grandmother to her-but shortly after the birth, the mother moved without any address left. Over the years, I asked around town to try and find my son's exwife(前妻), but it seemed that she didn't want to be found.     I'd just joined this new church a week earlier, and was at once offered the part of Grandma in the play. At least now I could pretend to be a grandma. The rehearsals went well, and finally the day of the show arrived. The performance was great. "You all looked so natural up there," one of my friends said.     Afterward, we went to the church basement for refreshments(茶点). I walked over to one of the girlsin the play, Rehearsals had been such a whirlwind(一片忙乱) that we never really got to talk. "How's my granddaughter?" I joked.     "Fine!" she answered. Just then, someone else walked up and asked the girl her name.     I wasn't sure I heard the girl's answer correctly. But it made me ask her another question. "What's your mother's name?"      She told me, I was still in shock. "And what's your father's name?" I asked. She told me. It was my son.      She'd only started going to that church a week before I did. Since that day of the play, we've stayed close. Not long ago, she even made me a great grandma.1. What was the author doing at the beginning of the story?A. Telling a story.  B. Playing a game.C. Preparing for a play.  D. Acting in a movie. 2. Why did the author feel "A pang of sadness" at the words of the director?A. The director's words reminded her of her lost granddaughter.B. The director's words hurt her so badly.C. She wished that she had a real grandchild.D. The director wasn't content with her performance. 3. What happened in the church basement after the play?A. The author played a joke on Lena.B. Lena treated the author as a friend.C. The author got to know who Lena was.D. Lena mistook the author for her grandmother. 4. This passage is mainly organized in the pattern of ________.A. time and events  B. contrast and conclusionC. cause and effect  D. questions and answers 5. We can infer that when writing the story, the author felt ________.A. lighthearted  B. heartbrokenC. confused  D. anxious