Câu hỏi:

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

Climate change is caused by the (1) _______ high levels of dangerous chemicals in the atmosphere, particularly carbon dioxide. It is estimated that average global temperatures will rise (2) _______ between two and six degrees by the end of this century. We all know the effects could be catastrophic, but are we (3) _______ of the possible solutions? Crazy as it sounds, a group of academics from British universities is making a plan to build a 12 -mile pipe, held up by a huge balloon, that would pump (4) _______ quantities of toxic chemicals, such as sulphur dioxide, into the atmosphere. Surprisingly, there is good science behind the idea. The chemicals would form a (5) _______ layer around the earth that would reflect sunlight and so cool the earth, much like the effects of a volcanic eruption.