Find the mistake in each of the following question. 

The assumption that smoking has bad effects on our health have been proved.

Find the mistake in each of the following question. 

A novel is a story long enough to fill a complete book, in that the characters and events are usually imaginary.

Choose the correct answer to each of the following questions.

His letter is full of mistakes. He _____ the mistakes carefully before sending it.

Choose the correct answer to each of the following questions.

________ have enough apples, she’ll make an apple pie this afternoon.

Choose the correct answer to each of the following questions.

If you don’t know how to spell a word, you ______ look it up in the dictionary.

Find the mistake in each of the following question. 

Developing new technologies are time-consuming and expensive.

Choose the correct answer to each of the following questions.

The computer has had an enormous _________ on the way we work.

Choose the correct answer to each of the following questions.

His letter is full of mistakes. He _____ the mistakes carefully before sending it.