某温度下,反应H2(g)+I2(g) 2HI(g)在密闭容器中达到平衡,缩小容器体积,增大压强,则下列说法正确的是( ) A.平衡正向移动
蜜蜂的足上有适于采集花粉的花粉筐,并以花粉酿蜜作为食物,有的植物的花能产生大量的花粉,并借助一定的形态结构吸引蜜蜂为传粉。这些事实说
接种卡介苗一段时间后,血液中就会出现结核杆菌抗体。这种抗体的基本单位和产生抗体的细胞及细胞器依次是( ) A.氨基酸、效应T细胞、核糖体 B.
胡辣汤是河南人喜爱的汤类名吃之一,制作胡辣汤的主要原料有面粉、粉条、豆腐丝、胡椒粉、牛(羊)肉、食盐等,上述原料中富含糖类的是_______你
Because the shop____,all the T-shirts are sold at half price. A. has closed down B.closed down C.is closing down D.had closed down
— Where is the School English Speech Contest going to be held tonight? — I’m not sure. Is it in the hall _____ can hold 300 people? A. where B. what
已知a=(2,-3,5),b=(-3,1,-4),求a+b,a-b,|a|,8a,ab.
用“<”或“>”填空: 若a<0,b 0时ab≥0