有一辆质量为1.2×10³kg的小汽车驶上半径为90m的圆弧形拱桥．求：

    Anne and Sue are good f____. They have the s____ age. They are both twenty-two. They both like sports. Most important, they both like new dresses. They usually go s____ together at weekends. Now they are in a c____ shop. There are d____ kinds of beautiful dresses. Anne wants a red dress. But Sue thinks the pink o____ is better.

下列材料中：①高分子膜；②生物高分子材料；③隐身材料；④液晶高分子材料；⑤光敏高分子材料；⑥智能高分子材料。属于功能高分子材料的是(　　)

我国社会主义制度基本建立的标志是（    ）