My friend Jack always ________ a smile ________ his face.

People can unlock the shared bikes, _________are equipped with GPS and can be left anywhere in public, by simply _________their smart phones.

errible accident is underinvestigation.—Actually, quicker action _____ thoseworkers trapped in the mine.

I listened to a report about the Diaoyu Island Dispute last weekend and that was the first time Iabout the subject

The teacher asked me .