John is the only one of the students in the class that never_____ a mistake even when it is pointed to him.
It is hoped that there will be ____ time in the future when ____ man can defeat cancer.
Scientists warn us _____ the need to keep an eye ____ the greenhouse effect.
The old temple, which ______ to the 17th century, needs to be repaired.
---Who do you think should ____ the responsibility for white pollution? --- Both the producer and the consumer.
I would rather you _____ the truth now instead of afterwards.