老师演示了如何使用这台设备。

___The ___teacher ___demonstrated how to use the equipment.

他找到了一份在百货公司演示厨房电器的工作。

He got a job ___demonstrating kitchen appliances in a department store.

在研讨会上，她将演示编程的基本原理。

In the workshop, she will ___demonstrate the basic principles of coding.