1792年《美利坚合众国宪法》第十条修正案规定：“宪法未授予合众国、而又未禁止各州行使的权利应由各州或其人民保留之。”该宪法修正案确立的新体制是(  )

已知直线$l_1:4x-3y+6=0$和直线$l_2:x=-1$，抛物线$y^2=4x$上一动点P到直线$l_1$和直线$l_2$的距离之和的最小值是（    ）

    There have been many comparisons (比较) made between London Underground and New York Subway. They are the best known public transport systems (公共交通运输系统) in the world and each is a key part of one of the greatest cities of the world. The two systems have many things in common(相同), including their ages and fame（名声）, but there are also important differences.

    The following table shows some of the similarities (类似）and differences.

科学家们将男性、女性体细胞内的染色体进行整理，形成了下列排序图．请观察分析回答有关问题．