百度试题 题目What is the atomic number of oxygen?A、2B、6C、8D、20Answer:C 科目四考试网___科目四考试题库相关知识点: 试题来源: 解析 http://www.km4ks.com/st/tk/ 反馈 收藏
Mass number is the total count of both protons and neutrons in an atom. This is helpful when identifying different isotopes of an element. While the number of protons remains the same for all isotopes, otherwise the atom would change elements to one with a matching number of protons, the ne...
A. what B. which C. that D.it 相关知识点: 试题来源: 解析 3.C 【解析】考查定语从句的关系词。 句意:氧气是能助 燃的唯一气体吗?先行词为gas,指物,该空在从句中作 主语,不可省略,且先行词前有 the only 修饰,引导词只 能用 that 而不能用 which。 故选 C。 反馈 收藏 ...
Yougaingreaterconfidenceinyourself.Also,youbecomemoreoptimisticandcalmerinthemindthanbefore.Thereareseveralreasonsforthesechanges:yourself-imageimprovesasyoustartlivingintidybeautifulrooms,andyougaindecision-makingskillsasyoucontinuetochoosebetweenwhichthingstothroworgiveawayandwhichtokeep.ThewayweletgoofthingsintheKo...
[解答]答案:C这个句子的主语是water,谓语是will continue to be,表语是what it is today,补语是next in importance to oxygen.what 在句子中表示"什么的样子"就像She is no longer what she was ten years ago.她不再是十年前的样子了.as 不能引导表语从句.
相关知识点: 试题来源: 解析 B。原因:文中提到“In industry, oxygen has many applications. It is used in steelmaking to remove impurities from iron. It is also used in the production of chemicals such as sulfuric acid.”。 反馈 收藏
The mass number of an atom is the total number of protons and neutrons contained within the nucleus of the atom. The number of protons determines the element and will always equal the atomic number of that element. The number of neutrons can change and will determine which isotope of that ...
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解析 C 关系代词what在这里引导一个名词性从句作to be的表语,同时what在表语从句中又为is的表语成分,这类语法结构还有,如:Show what you have written.(把你所写的给我们看看)和She is not what she was a few years ago.(她可不是几年前的她了)。其他选项均不能表示这种语法关系。
Fish ___ oxygen through their gills(鳃). III.单项填空: () 1. Air pollution can affect humans by___ sore eyes and respiratory problems, especially in children and___. A. cause, the old B. causing, the older C. causing, the elderly D. cause, the elderly ()...