把一个长方形卷起来,可卷成( )个不同圆柱的侧面.
2
短周期元素X、Y、W、Q在元素周期表中的相对位置如图所示.常温下,Al能溶于W的最高价氧化物的水化物的稀溶液,却不溶于其浓溶液.下列说法正确的是( )
A.Y的最高化合价为+6
B.离子半径:W>Q>Y>X
C.氢化物的沸点:Y>Q
D.最高价氧化物的水化物的酸性:W>Q
It was a difficult time, but in the end things _____ all right. [ ]
A. turned up
B. turned on
C. turned out
D. turned in