两广总督李侍尧在乾隆二十四年(1759年)的奏折中说:“外洋各国夷船到粤,贩运出口货物,均以丝货为重,……统计所买丝货,一岁之中,价值七八
喝牛奶可以补钙,这里的钙指的是A.分子 B.原子 C.元素 D.单质
阅读下面文字,完成下列小题 齐白石授徒时有一句名言:“学我者生,似我者死。”李苦禅谨记老师的这句话,因此他学的是老师独到的艺术匠心,而
(08广安)在一个重2N,底面积为0.01扩的容器里装8N的水,容器中水的深度为0.05m。,把它放在水平桌面上,如图12所示(g=1ON/kg)。求:(1)水对容器底
The students were all tired, but ___ of them stopped to have a rest.A.noneB.eachC.eitherD.neither
He lay in bed, with his eyes ______ up at the ceiling and his fingers ______. A. looked; crossing B. looking; crossing C. looking; crossed D. looked; crossed
化学与环境密切相关.下列有关说法错误的是( ) A.CO、NO能与人体的血红蛋白结合,使人中毒 B.CaO能与SO2反应,可作工业废气的脱硫剂 C.光化学
函数y=log3(x2-2x)的单调减区间是________.