下列说法中正确的有（　　）

①±2都是8的立方根，②$\sqrt[3]{x^3}$=x，③$\sqrt{81}$的立方根是3，④-$\sqrt[3]{-8}$=2．

根据短文内容及首字母提示,补全空格内单词，使短文完整、通顺。

    Walden is a quiet small town in England. Cars c____ go into the centre of the town, so it is very pleasant to walk around.

    Spend at least half a day v____ the museum. It's on a hill outside the town in a lonely old building. The museum brings history to life. You can even ride on a horse and cart(马车) in the street. I was r____ interested in a 1950s living room in the museum. It was just l____ my grandmother's house. I lived there when I was a c____ .

    If you can't wait, there is a new exhibition(展览) opening soon. Walden is f____ for one thing—candy! If you like candy, this exhibition is the place for you. You can learn about its history. I n____ see so many different kinds of candies.

    But I won't go now b____ it will start on the 26^th of May.

    When you are there, have a look around Walden too. If you start in the main square and follow the green signs, they will t____ you to the museum, and you will see lots of other interesting things o____ the way, too.

如图所示的电路为演示自感现象的实验电路，若闭合开关S，电流达到稳定后通过线圈L的电流为I₁，通过小灯泡L₂的电流为I₂，小灯泡L₂处于正常发光状态，则下列说法中正确的是（   ）

已知定义在R上的函数$f\left(x\right)$、$g\left(x\right)$满足$\frac{f\left(x\right)}{g\left(x\right)}=a^x$，且$f^{\text{'}}\left(x\right)g\left(x\right)<f\left(x\right)g^{\text{'}}\left(x\right)$， $\frac{f\left(1\right)}{g\left(1\right)}+\frac{f\left(-1\right)}{g\left(-1\right)}=\frac{5}{2}$，若有穷数列$\left\{\frac{f\left(n\right)}{g\left(n\right)}\right\}$（$n\in N*$）的前n项和等于$\frac{31}{32}$，则n等于（ ）

判断下列图片与单词是否相符，用”正确”或”错误”表示。