下列黄酮类化合物中具有雌激素样作用的是
A．槲皮素B．大豆素C．红花黄素D．花青素E．儿茶素
参考答案：B
按（）划分，城市中心可分为行政中心、体育中心、科技中心等。
A.规模
B.服务范围
C.级别
D.使用性质
—I called you at six o'clock yesterday evening but there was no reply.
—Oh, I'm sorry. I _______ dinner at my friend's. [ ]
A. was having
B. is having
C. had
D. have
