A:1
B:12
C:13
D:-1
已知f(x)=x2+2(a﹣2)x+4,如果对x∈﹣3,1,f(x)>0恒成立,则实数a的取值范围为 ____.
阅读下面文言文,回答后面小题。子曰:“学而时习之,不亦说乎?有朋自远方来,不亦乐乎?人不知而不愠,不亦君子乎?”子曰:“温故而知新,可以为为师矣。”子曰:“学而不思则罔,思而不学则殆”。子贡问曰:“孔文子何以谓之‘文’也?”子曰:“敏而好学,不耻下问,是以谓之‘文’也。”子曰:“默而识之,学而不厌,诲人不倦,何有于我哉!”子曰:“三人行,必有我师焉;择其善者而从之,其不善者而改之。”——《论语》
五位中国学生要去美国留学,他们想要找住家。请仔细阅读第1-5题中的学生的个人情况说明,并从A至F六个选项中,帮助他们选择最适合的住家(其中一项为多余选项)____ Zhang Chao likes Chinese food. He hopes his host family speak a little Chinese.____ Li Wei likes doing sports. He wants to live near a park.____ Liu Yong hopes to live near his school---Reading School. He prefers a bed room with a bathroom____ Chen Yao wants to live in a big bedroom cheaper than £350 a month. She can’t stand pets.____ Hu Mei loves pets. She would like a bedroom cheaper than £220 a month.