3.3.3It can be inferred from the passage that a taxi driver hears the same voices () every day.

1.7题目:Color blind people often find it difficult to () between blue and green.

1.6题目:When he was questioned about the missing ring， he firmly()that he had ever seen it.

1.5题目:The teacher asked each of us () what he had been doing.

1.4题目:Water encourages the () of iron and oxygen to form rust.

1.3题目:I have to book ahead for concert， () are usually held in London.

1.2题目:Can you tell me () about this city that makes people love it so much?

1.1题目:During the () two decades， research has greatly expanded our knowledge about the sleep and dreams.