Use different kinds of fossil fuels has been the main cause of climate change.

Choose the best answer.

If a machine stops moving or working normally, you can say that it has ______ .

Find the mistake.

Perhaps the most distinctive features of insects and undoubtedly one of the most important reasons for their success is their quite well-developed sensory system.

Choose the best answer.

You may find doing this job very _______. Try it!

Choose the best answer.

In 1791, Pierre-Charles L' Enfant ________ plan for the new capital city at Washington.

Choose the word CLOSEST in meaning to the underlined part.

The architect was let down that his new city plan had been turned down.

Choose the best answer.

Turn off this machine, please. The harsh sound really _______ me crazy.

Choose the word OPPOSITE in meaning to the underlined part.

Vietnamese have a strong sense of hospitality and feel embarrassed if they cannot show their guests full respect by preparing for their arrival.