题目

As warming continues, scientists warn the oxygen content of oceans across the planet could be more and more reduced, with serious consequences for the future of fish and other sea life.【1】One is the simple fact that as water gets warmer, it can hold less dissolved (溶解的) oxygen. The other reason is less obvious. The entire ocean gets its oxygen from the surface — either from the atmosphere, or from photosynthesizing algae floating at the top of the sea. 【2】Global warming is expected to reduce the mixing of the ocean by making surface seawater lighter. That’s because in a warme12．雾霾天气可导致儿童紫外线照射不足，体内维生素D生产不足，对钙的吸收大大减少，严重的会引起婴儿（　　）A．佝偻病B．坏血病C．侏儒症D．自闭症