Li Ming, how are you getting _____ with your study? [ ]
A. at
B. in
C. to
D. on
答案:D
A、B两地相距1000米,甲、乙两人从A、B两地相向而行,相遇时所行路程的比是5:3,甲、乙各行了多少米?
若已知X、Y、Z、W四种金属与化合物之间存在化学反应有:①Y+ZCl2═Z+YCl2、②X+ZCl2═Z+XCl2、③Y+2HCl═YCl2+H2↑、④W+YCl2═W Cl2+Y;又知X与稀盐酸不能发生反应.试推断X、Y、Z三种金属的活动性由强到弱的顺序是( )
A.Z>W>Y>X
B.X>Y>W>Z
C.W>Y>X>Z
D.Y>Z>X>W