1. (2022高二下·上海期中) After reading the passages below, fill in the blanks to make the passages coherent and grammatically correct. For the blanks with a given word, fill in each blank with the proper form of the given word; for the other blanks, use one word that best fits each blank.

A rare hole has opened up in the ozone layer above the Arctic, in scientists say is the result of unusually low temperatures in the atmosphere above the north pole.

The hole has reached record dimensions, but is not expected to pose any danger to humans it moves further south. it extends further south to overpopulated areas, such as southern Greenland, people will be at increased risk of sunburn. However, on current trends the hole is expected to disappear altogether in a few weeks.

Low temperatures in the northern polar regions led to an unusual stable polar vortex (极地漩涡), and the presence of ozone-destroying chemicals such as chlorine (氯) in the atmosphere - from human activities-caused the hole (form) .

It is now too early to say the unusually stable Arctic polar vortex conditions are linked with the climate crisis, or part of normal stratospheric weather variability. Peuch said there were no direct implications for the climate crisis. Temperatures in the region are already increasing, (slow) the destruction of ozone.

a hole over the Arctic is a rare event, the much larger hole in the ozone layer over the Antarctic has been a major cause for concern for more than four decades. The production of ozone-destroying chemicals (reduce) dramatically, under the 1987 Montreal Protocol (蒙特利尔协议) , but some sources appear still to be functioning.

New sources of ozone-destroying chemicals were not a factor in the hole (observe) in the Arctic, said Peuch. "However, this is a reminder that one should not take the Montreal Protocol measures for granted, and that observations from the ground and from satellites are central to avoiding a situation the ozone-destroying chemical level in the stratosphere could increase again."