(____) I'm looking out of the window.
(____) Some children are making a snowman.
(____) In this photo,we are in the mountains.
(____) The wind is blowing and the sun is shining.
(____) I am having a lovely time.
世界上第一个把圆周率的数值精确计算到小数点以后第七位的是( )
用化学用语填空.
(1)氮元素: ____.
(2)铝离子: ____.
(3)甲烷:____.
(4)高锰酸钾: ____.
给希望小学送礼物,我们可以送( )。