补全短文
People are becoming very aware of the dangers of secondhand smoke. ________.
A、As a result, they have passed laws which prohibit people from smoking in many public places.
B、This smoke is called secondhand smoke.
C、It is even harder for children to avoid secondhand smoke.
D、Scientists did not think that these chemicals could harm a nonsmoker’s health.
【正确答案】 A
【答案解析】 前一句讲的是人们逐渐意识到二手烟的危害性，因此接下来应首选表示人们采取措施，禁止公共场所吸烟的句子。
