数一数,有多少只 ?
____ ____
构成叶绿素分子不可缺少的无机盐离子是( )
在经纬网中有两条经线和一条纬线是不用标注东西经或者南北纬它们是( )
①0°经线 ②0°纬线 ③180°经线 ④20°经线
用化学用语填空:
(1)磷的元素符号为____ ;(2)两个锌离子 ____ ;
(3)二氧化硫中硫元素显+4价 ____ ;(4)13号元素原子的结构示意图为____ ;
(5)空气中含量最多的气体是____ ;(6)人体胃酸的主要成分是 ____ .
两会是“全国人民代表大会”和“中国人民政治协商会议”的简称,每年3月份两会先后召开全体会议一次,每____年称一届,每年会议称×届×次会议,今年两会是第_______届。( )
It's Sunday afternoon. The weather is fine. There is a football match between class 2 and class 4. Many students are watching. They're excited. Now, Zhang Wei has the ball. He passes it to Wei Kun. But Wei Kun can't kick the ball. Then John has the ball. The ball flies to Zhang Wei's arm. Zhang Wei is very angry. The ball files into the goal. How is Zhang Wei feeling? He is so happy! Class 4 won the game. Class 2 is very sad.