单项选择题
A．It becomes invisible. B．It falls to Earth. C．It burns up all of its gases. D．It becomes brighter and easier to se
A．Sentence 1. B．Sentence 2. C．Sentence 3. D．Sentence 4.
A．They make him feel at home. B．He thinks they should be ignored. C．He believes they are part of our lives. D．He prefers silence to loud noises.