单选题 13. Observations of the Arctic reveal that the Arctic Ocean is covered by less ice each summer than the previous summer. If this warming trend continues, within 50 years the Arctic Ocean will be ice free during the summer months. This occurrence would in itself have little or no effect on global sea levels, since the melting of ice floating in water does not affect the water level. However, serious consequences to sea levels would eventually result, because ______.
Which of the following most logically completes the passage? ______

A、 large masses of floating sea ice would continue to form in the wintertime
B、 significant changes in Arctic sea temperatures would be accompanied by changes in sea temperatures in more temperate parts of the world
C、 such a warm Arctic Ocean would trigger the melting of massive landbased glaciers in the Arctic
D、 an ice-free Arctic Ocean would support a very different ecosystem than it does presently
E、 in the spring, melting sea ice would cause more icebergs to be created and to drift south into shipping routes

【正确答案】 C

【答案解析】 C：根据本文，海洋浮冰的减少不会影响海平面，但是该选项增加了大陆冰川融化这一条件，增加了海平面受到影响的可能，正确。
A：本文讨论的是为什么冰少了还会对海平面产生影响，该选项讨论的是冰形成的情况，无关，不选。
B：本文仅仅讨论温度的变化，和海平面无关，不选。
D：该选项讨论的是生态，和本文无关，不选。
E：本文没有提到冰川向南漂移与海平面有什么关系，不选。