Although he was in poor health, Robert succeeded_____other more famous engineers failed.
.Life is too short to waste and too ________ to give up.
The law required that everyone ________ his car checked at least once a year.
.Our teacher is very busy.He is ________ in working out a teaching plan.
Beijing Man used fire for cooking food and also for light, warmth and ________ wild beasts.
The doctor strongly recommended that he ________ a holiday.