This is a great TPR（Total Physical Response，全身反应法） activity that enforces actions and body parts (in particular) really well.

How to play: One student is the teacher and tells the other students to do something: "Teacher says: touch your nose." The other students must touch their nose. Any students who don't do it must sit down. If the teacher (or student being the teacher) doesn't say "teacher says" before they say "touch your nose", then any students who touch their nose must sit down. IE the students only do what they are told if the command if preceded by "teacher says".

The last student standing is the winner.

Variations:

When the teacher gives a command they could demonstrate the command as well. IE "Teachers says: run!" Then the teacher demonstrates by running. The teacher should demonstrate the action even if they didn't say "teacher says", just to try and trick some of the other students.
Using the method above, demonstrate commands different to what you say. IE "Teacher says: touch your nose." To trick some students, the teacher could touch their ears.
Enjoy!

英语口语教学