Would you like to go to the open-air concert at school? It’ll start in ________ hour and ________ half.

I began to teach ________ English when I was twenty-two years old.

Students ________ play with fire in the classroom. It’s quite dangerous.

The Forbidden City (紫禁城), the largest palace in the world, ________ more than 600 years ago.

Neither Saturday nor Sunday________ OK because I will be quite busy these two days.