语法填空

    阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。

    In China, there are ____(variety) means of transport for day-to-day living: subways, buses, cars, and even bikes… but taxis rank high on the list.

    Taxis are certainly the most convenient, as ____requires little effort to raise your arm to call a cab. Besides, fares in China are affordable. They start in daytime hours in the capital at 13 yuan for ____first 3 kilometers, after ____you pay another 2.3 yuan per kilometer. This is far ____expensive than that in European capitals. In London, for example, two kilometers' ride could cost you about 63 yuan.

    Taxicabs , as we know today, first appeared in China in the early 20th century, but ____(be) the reserve (特权) of the rich and the powerful. Nowadays, taking a cab is common in China.

    Before coming to China, I ____(warn) that there were awful drivers who would make long detours (绕行) ____ (get) higher fares. ____, most taxi drivers I have met are nice. They know the city like the back of their hands, and are glad to be ____some help.

已知f（x）=$x^{-t^2+2t+3}$为偶函数（t∈z），且在x∈（0，+∞）单调递增．

（1）求f（x）的表达式；

（2）若函数g（x）=log_aa$\sqrt{f\left(x\right)}$﹣x在区间2，4上单调递减函数（a＞0且a≠1），求实数a的取值范围．

有人说：《天朝田亩制度》实际上是一个和谐社会的公平的经济制度；也有人说它是近代民主革命中一个科学的政治纲领。你认为下列关于《天朝田亩制度》的认识，不正确的是