从C、H、O、N、S、Fe六种元素中,选择适当元素组成化学用语,按要求填空.
(1)用适当的化学符号和数字填空:①4个铵根离子_____;②3个三氧化硫分子_____.
(2)写出符合下列要求的物质的化学式:①相对分子质量最小的氧化物_____;②菱铁矿石的主要成分_____.
党的第十八届三中全会指出,我国的基本经济制度是中国特色社会主义制度的重要支柱,也是社会主义市场经济体制的根基,必须坚持和完善。我国的基本经济制度是
阅读理解,根据短文内容判断正(T)误(F)。
It'sSundaymorning.ThestudentsofClass3aregivingtheirclassroomagoodcleaning.
MissHuang,theirteacher,isworkingwiththem.Thechildrenarebusy.Somearecarryingwater;
somearecleaningthewindows;othersaresweepingthefloor.ZhangHuaisputtingupamaponthe
wall.ItisamapofChina.WangFeiandWeiQingaremendingsomebrokenchairs.Thechildrenare.
listeningtotheradiowhiletheyareworking.Theclassroomlooksniceandbrightafterthecleaning.
Thechildrenareveryhappy.Theygohomeforlunchatnoon.
()1.ThechildrenareplayingintheirclassroomonSundaymorning.
()2.MissHuang,theirmother,isworkingwiththem.
()3.ThereisamapofChinaonthewall.
()4.Twoofthemarerepairingthebrokenchairs.
()5.Theyaresingingwhiletheyareworking.