Find the mistake.

Cheap public transportation was highly encourage to use ten years ago, and air pollution has been reduced since then.

Choose the best answer.

They ______ in the suburbs of the city since they ______ their house in the center in 2019.

Choose the best answer.

Some parents are worried about their children’s ______ when they go online too much but rarely communicate with their parents face-to-face.

Choose the best answer.

He ______ his report on the city planning, so he can have free time and relax now.

Choose the best answer.

______ have enough fresh air to breathe, people should plant more trees around the places where they live.

Choose the word CLOSEST in meaning to the underlined part.

Some people don’t feel secure when living in big cities with high crime rates.

Choose the best answer.

Smoke detectors should be installed in high buildings ______ warn people about fires.

Choose the best answer.

______ be addicted to social media, teenagers should spend less time surfing the Net every day.