When a spacecraft travels, one of the major problems is reentry into the Earth ’s _______.

If you have any problems during your study here,please do not _______ to call me for help

With the _______of Mary, all the girl students are eager to go to the party.

He _______ to study harder in the future so that he could have more opportunities to find a better job.

Carelessness made him fall in his job _______.

I have not heard anything from him since his _______.

Please be serious. I am not _______. You should consider it carefully

Many kinds of animals are believed to have _________from the earth

We won ’t allow any foreign country to _______ in our internal affairs.

Some lazy men would rather _______ than work.