(10分)在标准状况下，将CO2 与CO的混合气(其质量为同状况下等体积氢气质量的16倍)充满盛有足量过氧化钠的容积为2.24L的密闭容器内。(设固体物质的体积
— Dear, what time is the flight to Beijing on Saturday? — Wait a minute. Let me _______ in the schedule（时刻表）. A. look at it B. look for it C. look after it
Mr. King works very long hours every day. He usually gets up at 5:30. He brushes his teeth quickly and goes to his workplace (工作地点). Then he runs with some kids. After that he takes a shower.
向三份0.1mol·L-1 CH3COONa溶液中分别加入少量NH4NO3、Na2SO3、FeCl2固体（忽略 溶液体积变化），则CH3COO- 浓度的变化依次为 A．减小、增大、减小 B
Scientists are convinced ___________ the positive effect of laughter ___________ physical and mental health. A. of; at B. by; in C. of; on D. on; at
Frank Woolworth was born in Rodman, New York, in 1852. His family were very poor farmers, and there was never enough to eat. Frank decided he did not want to be a farmer. He took a short business cou
下列物质中铁的质量分数最小的是 A.FeO B. Fe3O4 C.FeS D.Fe2O3
光在真空中传播速度为_____m/s;为实现我国的探月计划，向月球发射的激光到达月球并返回地面共需2．56s、则地球和月球间的距离是______m。
的绝对值等于 。
