According to the third paragraph,what will happen when the underground heat does not dis—appear? Coal heats up on its Own and catches fire and burns. 。 The underground oxygen will be used up.。 Poisonous fumes and greenhouse gases wm be accumulated anderground. 。 There will be an increase of abandoned mines. 。
请在第__65__处填上正确答案。 performed。 studied。 brought。 taken。
请在第__57__处填上正确答案。 putting。 covering。 cheating。 tricking。
According to the passage, it may soon be possible__________ to make something as good as human skin。 to produce drugs without side effects。 to transplant human organs。 to make artificial hearts and eyes。
请在第__62__处填上正确答案。