近年来,我国逐渐提高了磷矿石、玉石、珍珠岩等矿产资源税,提高金属矿、非金属矿的采选产品的增值税税率,这有利于( )
①减少矿产开采,合理利用资源 ②节约资源,转变发展方式
③保护环境,促进采矿利润增长 ④开发新矿,促进经济健康发展
A:①②
B:③④
C:①④
D:②③
小文同学在探究物体做曲线运动的条件时,将一条形磁铁放在桌面的A位置,让小钢珠在水平桌面上以初速度v0运动,得到小钢珠的运动轨迹.图中a、b、c、d哪一条为其运动轨迹( )
读一读,连线。
①What do you like doing? ____ A.It's white and yellow.
②Do you like this pear tree? ____ B. Yes, it does.
③What colour is this flower?____ C.Yes, I do.
④Does it have long leaves? ____ D. They need water.
⑤What do the plants need?____ E. I like listening to music.
7cm=____m 49dm=____m
6元3角=____元 450kg=____t