Find a mistake in the four underlined parts of each sentence.

 It is reported (A) that six people trapped (B) in collapsed (C) buildings have freed (D) so far. 

Choose the correct answer A, B, C or D to complete each sentence.

Artificial Intelligence (AI) is an area of __________concerned with making computers copying intelligent human behaviour.

Choose the correct answer A, B, C or D to complete each sentence.

 Computers that once ___________ up entire rooms are now small enough to put on desktops and into wristwatches.

Choose the correct answer A, B, C or D to complete each sentence.

A forest fire ________ quickly and ________ many trees.

Choose the correct answer A, B, C or D to complete each sentence.

The tornado caused a massive ________ to the town.

Choose the correct answer A, B, C or D to complete each sentence.

Hemp was grown throughout history ________ its versatility; it can be used to make many different things.

Choose the correct answer A, B, C or D to complete each sentence.

Global warming ________ if there weren't too much carbon dioxide in the atmosphere.

Choose the correct answer A, B, C or D to complete each sentence.

 Passengers __________ to smoke in the train.