few years, the coal workers___________ their lungs X-rayed to ensure their health.

Tom was so careless with his spelling that he often _______letters from words.

Lily doesn’t know ________ she and her friends can do to help the little boy ________ parents have left their hometown for making money.

Normally, students will be given a certificate ______completion of the course

下列各句句式和例句不相同的一项是（ ）例句：奚以知其然也