下列物质溶于水时，溶液温度明显降低的是（　　）

近年来，许多用人单位对高校女生就业歧视日趋严重，在他们看来男生更能吃苦，并且不会因生理、婚姻、生育等因素给单位造成损失。上述现象    (    )

平面直角坐标系xoy中，椭圆C₁： $\frac{x^2}{a^2}$ + $\frac{y^2}{b^2}$ =1（a＞b＞0）的离心率为 $\frac{\sqrt{2}}{2}$ ，过椭圆右焦点F作两条相互垂直的弦，当其中一条弦所在直线斜率为0时，两弦长之和为6．

    Now you may find that more and more children arc becoming very heavy．Why? Maybe there're three main ____ ．

    Firstly，there are too ____ shops around schools．The shops sell unhealthy foods，such as fried chicken and ice cream at low prices．So some children don't like to eat at home．If there are fewer of these shops，then probably children will ____ less unhealthy food．

    Secondly，children have ____ eating habits．They like fast food．Today we can see McDonald's and KFC everywhere．Many children like fast food very much．In fact．most of the fast food is unhealthy ____ it has too much salt（盐），sugar and fat(脂肪)．

    Thirdly，these days children ____ little exercise．When they get home，they sit before the televisions or their computers and play computer games．It's not a good habit，and it also gives them time to eat more unhealthy food．They should go ____ and play sports or games．

    For children's health，parents should ask children to do more sports and eat ____fast food．