题目

阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空。Throughout their history, Americans 【1】 (be) people on the move over the past 200 years. When the early immigrants arrived in the New World, they settled along the East Coast. But they weren't content【2】 (stay) there. Later, they moved westwards to develop these new areas and【3】 (final) occupied the whole continent from the Atlantic to the Pacific. Even today, Americans seem 【4】(able) to stay in one place. It is sai如图，一个矩形纸片，剪去部分后得到一个三角形，则图中∠1+∠2的度数是（ ）A. 30° B. 60° C. 90° D. 120°