国家开发投资公司是央企中唯一的投资控股公司，其管理的先进制造产业投资基金，由中央财政出资60亿元、国投出资40亿元和社会募资100亿元组成。该基金主要投向高端船舶和海洋工程、工业机器人等与“中国制造2025”相吻合的行业。材料表明

①混合所有制经济是我国社会主义市场经济的根基（  ）

②非公有制经济对我国先进制造业的支撑作用越来越大

③国有经济对我国战略性新兴产业的发展起着主导作用

④公有制为主体、多种所有制经济共同发展是我国的基本经济制度

若tan$\alpha$=3，则$\frac{\sin 2\alpha }{{\cos }^2\alpha }$的值等于(    )

    In the Charles E. Johnson Elementary School in New York, there is a special radio. It gives people warnings (警报) about bad weather.

    One day, there came a sound from the radio. This sound brought the piece of news: a heavy storm was coming. William Tomic, principal (校长) of the school, he asked teachers to bring children indoors and put them in a safe place at once.

    Minutes later, the storm came. However, because of the warning of the radio and the quick work of the principal, no one was hurt. “The radio really did work very well. 我们对它的工作感到很高兴,” William Tomic said. “The parents were as well.” The US government hopes there will be more such success stories. It plans to give this kind of radios to all 97, 000 public schools in the country.

    Every year, more than 10,000 big thunderstorms, 2,500 floods, 1,000 tomatoes (龙卷风) and some hurricanes (飓风) take place in the US, so the warning radios are very useful.

    They not only give people warnings about bad weather, but also give warnings about other dangerous things.

已知点A（1，2）是二元一次不等式2x﹣By+3≥0所对应的平面区域内的一点，求实数B的取值范围．