阅读判断。
    Jenny, Danny, Kim and Steven are good friends. Jenny and Kim are reading books in the library. Where are Danny and Steven? Look! They are playing a game on the playground. Who is in the classroom? It's Mr. Wood.

从实数﹣1、﹣2、1中随机选取两个数，积为负数的概率是____．

某同学在学习了金属及其化合物之间的转化规律后，给制了可以通过一步反应制取MgSO₄的思维导图，其中所选用的物质错误的是（    ）

飞机着陆后滑行的距离y（单位：m）关于滑行时间t（单位：s）的函数解析式是y=60t﹣ $\frac{3}{2}{t}^2$ ．在飞机着陆滑行中，最后4s滑行的距离是____m．

4＋4＋4＋4＋4改写成乘法算式是（）。