给出几种变换：（1）横坐标伸长到原来的2倍，纵坐标不变；（2）
横坐标缩小到原来的，纵坐标不变；（3）向左平移个单位；
（4）向右平移个单位；（5）向左平移个单位；（6）向右平移个单位，则由函数
的图象，可以实施的方案是

如今，民营资本进入的领域越来越多，中国的经济活力越来越强。目前，全国60%的GDP、70%的税收和80%的就业岗位都来自民营企业。这表明（    ）

①非公有制经济是社会主义经济的重要组成部分

②非公有制经济是我国经济社会发展的重要基础

③非公有制经济的发展有利于支撑经济增长、扩大就业

④个体、私营经济发展有利于增强市场活力、促进创新

将物质的量均为a mol的钠和铝一同投入m g水中(水足量)，所得溶液的密度为ρg·Cm^-3，则此溶液的物质的量浓度为（  ）

    It seems to be strange to you there is a blind spot(点) on the eyes. Here is an interesting experiment that can make something disappear, when one eye is open.
　Make a card about the size of a postcard and write two English letters L and R on it, L on the left and R on the right. First, hold the card about 80 cm away and you see both the letters. Then close your right eye and look at the letter R only with your left eye. And now, as you move the card slowly towards you, you'll find the letter L disappearing. But if you move the card nearer to your face, the letter will be seen again. Now do the same experiment with your left eye closed, you'll find the letter R disappearing.
    Why does the letter disappear? It is because there is a blind spot on the eye. When the image of the letter falls on the blind spot, it won't be seen. That is why either of the letters disappears.

下列各句中，划线的成语使用不恰当的一项是（ ）