The sentences on the blackboard are very important. Please __________in your notebooks.

He’shis purse,but he can’t it.

Waves of red light are about twice as long as _______ of blue light.

To save the drowning child, the boy plunged into the icy water without hesitation, _____ his own safety[ ]

_____ we celebrate a festival it changes a little and in that way we keep our culture _____ [ ]