A:所得溶液可能都是饱和溶液
B:20℃时,乙溶液的溶质质量最小
C:溶液溶质的质量分数:甲>丙>乙
D:升高温度,溶液溶质的质量分数一定变大
Sunday,June 1
Dear Tony,
Now we are having fun at Tian'anmen Square. The weather is fine. There are many people here. We'll visit the Bird's Nest and the Water Cube. In the evening,we'll have Beijing Duck. I love Beijing. I hope you will come to China soon.
Your friend,
Ben
Tony White__
78 Flower Road__
New York,CBE779D,USA
下列是穆罕默德宗教和政治活动的大事,按时间先后顺序排列正确的是( )
①出走麦地那②成为政治、宗教领袖③开始在麦加传教④基本统一阿拉伯半岛
实数a,b,c在数轴上对应的点如图所示,则下列式子中正确的是( )
如图为某种鱼饵自动投放器的装置示意图,其下半部AB是一长为2R的竖直细管,上半部BC是半径为R的四分之一圆弧弯管,管口C处切线水平,AB管内有原长为R、下端固定的轻质弹簧.在弹簧上端放置一粒质量为m的鱼饵,解除锁定后弹簧可将鱼饵弹射出去.投饵时,每次总将弹簧长度压缩到0.5R后锁定,此时弹簧的弹性势能为6mgR (g为重力加速度).不计鱼饵在运动过程中的机械能损失,求: