根据上面内容判断正误，正确的写（T），错误的写（F）.
     There are many clubs in our school. Let me tell you what they are.
     Do you like playing tennis? It's OK if you can't play tennis. Mr. Qing can teach you. Come and join the tennis club!
Do you like acting? Do you like to work with other young people? Do you want to be in the school play? Come and join the acting club.
Can you dance? Do you like Latin (拉丁) dance or Chinese traditional (传统的) dance? Join the dance club and dance for the Christmas (圣诞节) show.
    Do you like French food? Can you speak French? Do you want to learn French? Join the French club now.
____ Mr. Qing can teach you French.
____ If you join the acting club, you can act in the school play.
____ Christmas Day is coming.
____ You can learn French in the French club.
____ There are three clubs in the school.

有NH₄⁺、Fe³⁺、NO₃^﹣、Fe²⁺、H⁺和H₂O六种微粒，分别属于一个氧化还原反应中的反应物和生成物．

（1）氧化剂与还原剂的物质的量之比为____ 

（2）若有l mol NO₃^﹣参加反应，则转移____ mol e^﹣

（3）若把该反应设计为原电池，则负极反应为____ ．

如图所示，粗糙水平地面AB与半径R=0.9m的光滑半圆轨道BCD相连接，且在同一竖直平面内，O是BCD的圆心，BOD在同一竖直线上．质量m=2kg的小物体在水平恒力F=20N的作用下，从A点由静止开始做匀加速直线运动，已知x_AB=10m，小物块与水平地面间的动摩擦因数为μ=0.5．当小物块运动到B点时撤去力F．取重力加速度g=10m/s²．求：

130×7=____

120×6=____

270×3=____