Due to the widespread ________ of this medical technology, more diseases can be discovered and treated at an early stage.

It was very important for us ________ happy every day.

How long ago ______ you ______ the English Club? —I ______it since two years ago.

Boys, don’t touch the machine, or you may hurt _________.

Look at the lady there. ______ it be Miss Li? — No, it ______ be her. She left for Paris this morning.