Read the following paragraph and find TWO irrelevant sentences.

Read the following paragraph and find TWO irrelevant sentences. 　The Arctic is shaping up to be one of the most strategically important regions in the 21st century. However, while Russia has been steadily building its Arctic capabilities, the U.S. nearly lost its only heavy polar icebreaker on an Antarctica deployment. Russia plans on adding two icebreaking patrol ships armed with cruise missiles by 20Thankfully, the U.S. government is beginning to take this gap seriously and there are actions the government can take to accelerate this revitalization (振兴).First, the Coast Guard should consider purchasing foreign- built icebreakers. Also, Congress can work with the Coast Guard to facilitate more efficient business practices. Foreign-built icebreakers could be significantly less expensive. Finally, the government should increase the Coast Guard's total acquisition budget. If Congress and the executive branch do not act quickly to reverse the current trends, then the U.S. is partially losing the opportunity to be a key player in this strategic region.
【正确答案】： Russia plans on adding two icebreaking patrol ships armed with cruise missiles by 2020. Foreign-built icebreakers could be significantly less expensive.
【题目解析】：本段主要讲述的是北极地带已经成为21世纪最重要的战略区域之一，此为美国的具体战略举措。句子Russia plans on adding two icebreaking patrol ships armed with cruise missiles by 2020.（俄罗斯计划到2020年增加两艘配有巡航导弹的破冰船）。这是俄罗斯的具体做法，不符合主题，因此删去。
接下来文章讲述美国政府的三项战略举措。其中Foreign-built icebreakers could be significantly less expensive.（外国建造的破冰船要便宜得多）不符合主题，因此删去。