The teacher told his students the sun_____ in the east. 

The workers want us ________ together with them. 

— I must apologize for _____ ahead of time. — That’s all right.

（2011 • 哈尔滨三中10月测试）Please keep us __________ of any change of your address as soon as possible. 

 —Can those  at the back of the classroom hear me?—No problem, sir !