1 . 阅读下面短文, 在空白处填入 1 个适当的单词或括号内单词的正确形式。
Global warming is a gradual increase in the earth’s temperature, generally due to the greenhouse effect 1 (cause) by increased levels of carbon dioxide and other pollutants.
Temperatures and sea levels are rising, possibly contributing 2 more storms. The rising has influenced a lot, 3 (result)in a lot of climate problems, and humans are at least partially 4 (blame). Global warming causes climate change, 5 places a serious threat to life on the earth in 6 (vary) forms like widespread flooding and extreme weather. Climate experts 7 (gather) detailed observations of different weather 8 (phenomenon) since the mid-20th and of related influences on climate. Scientists have high confidence 9 global temperatures will continue to rise for decades to come, 10 (large)due to greenhouse gases produced by human activities.