With two children _____ middle school, theparents are working hard.

He had been _______ good terms with Tom, but all of ____ sudden they lost in touch with each other

Many of the big world sports events are _______by wealthy big companies, who hope to advertise their companies or their products.

There is no light on, they ____ be at home. [ ]

下列各句中，没有语病的一句是（ ）