What does the word “they” in paragraph 4 refer to?

Most young people want to ____ an independent life without being influenced by anyone.

Mark the letter A, B, C or D to indicate the underlined part that needs correction in each of the following questions.

As emissions increase, it trap more heat in the atmosphere, leading to a period of unprecedented warming.

Because of his disease, the doctor advised him to abstain from alcohol and meat. However, he seems not to follow this advice.

Mark the letter A, B, C or D to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.

Simon earned the respect of his friends when he determined to complete such a challenging task while others had already given up.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks.

Despite the wealth of information campaigns telling people about global warming and its causes, most people have (23) _______to realize how severe the problem is. Coming climate changes could alter as much as one third of plant and animal habitats by the end of the 22nd century. These changes could in (24) ____ cause widespread extinctions among plant and animal species around the globe.

Coastal and island habitats are perhaps in the greatest danger (25) _______ they face the combined threats of warming oceans and rising sea levels. As habitats change, many animals will come under intense pressure to find more suitable homes for themselves. Mass (26) ____ of at least some animals are certainly to be expected, but the fact remains that many animals will simply not be able to move fast enough.

Such dire predictions may sound alarmist, but they are based on the rather moderate estimate that the amount of carbon dioxide in the atmosphere will double by 2100. Many scientists believe, however, that this figure is actually very conservative, and they claim that a tripling is far more realistic. If they are (27) ____, the effects on nature will be even more dramatic.

(Source: https://www.nytimes.com/interactive/2017/climate)