When John left the room, he ________ take his things.   

平面直角坐标系中，直线l的参数方程是$\left\{\begin{array}{c}x=t\\ y=\sqrt{3}t\end{array}\right.$（t为参数），以坐标原点为极点，x轴的正半轴为极轴，建立极坐标系，已知曲线C的极坐标方程为ρ²cos²θ+ρ²sin²θ﹣2ρsinθ﹣3=0．

（1）求直线l的极坐标方程；

（2）若直线l与曲线C相交于A、B两点，求|AB|．

在古代中国政治文明的演进过程中，出现过许多重要的地方行政制度。以下对古代中国地方行政制度的论述，正确的是（   ）

根据短文，现在请同学们为Mr. Cao填完整他工作日的日程安排表
   Mr. Cao is a teacher in a middle school．He has a lot of things to do from Monday to Friday．On Monday and Tuesday morning he has three speaking classes．On Thursday he has two writing classes in the morning and one in the afternoon．He plays ball games after class on Monday and listens to music on Tuesday afternoon．He doesn’t have classes on Wednesday or Friday．He works on the computer on Wednesday morning．He can speak a little Japanese．So he takes Japanese classes that afternoon．On Friday morning．Mr. Cao meets old friends．In the afternoon，he has a rest at home

一弹丸在飞行到距离地面5m高时仅有水平速度v=2m/s，爆炸成为甲、乙两块水平飞出，甲、乙的质量比为3：1，不计质量损失，取重力加速度g=10m/s²，则下列图中两块弹片飞行的轨迹可能正确的是（   ）