题目

连词成句 51. Gina, to , you , nice, meet ________________________________________ . 52. color, are, pens, what, the ________________________________________ ? 53. her , name, is , Brown, family _________________________________________ . 54. your, he , cousin, is ______________________________________ ? 55. brother, are, those, sister, and, ,my _______________________________________________ .       设函数f(x)的定义域为R，若存在与x无关的正常数M，使|f(x)|≤M|x|对一切实数x都成立，则称函数f(x)为有界泛函，在函数(1)f(x)＝2x；(2)g(x)＝x2；(3)v(x)＝xsinx；(4)h(x)＝2x；中，属于有界泛函的有________(写序号)