【多选题】创建一个类的对象时,系统自动调用( );撤销对象时,系统自动调用( )。
【单选题】The following description of class selector of CSS is correct:
A.
Class selector names start with "#" followed by English symbols。
B.
Class selector names start with "." followed by an English symbol。
C.
Class selector only needs to be defined, and the style will change automatically after it is defined。
D.
When applying a class selector, you need to introduce a class selector through the ID attribute, such as < p id="class selector">。
【单选题】创建一个类的对象时,系统自动调用( );撤销对象时,系统自动调用( )。
【单选题】CSS selector types do not include which of the following options:
【单选题】当创建一个类对象时,系统自动调用【】并给予对象的数据成员进行初始化。
【判断题】可以采用Hinsberg反应来鉴别伯、仲、叔胺。
【单选题】from scrapy.selector import Selector htmlText=''' Harry Potter 29.99 学习 XML 39.95 ''' selector=Selector(text=htmlText) ____________________________________________________ print(s.extract_first()) s=s...
A.
s=selector.xpath("//book/title[@lang='chinese']/text")
B.
s=selector.xpath("//book/title[lang='chinese']/text")
C.
s=selector.xpath("//book/title[@lang='chinese']/text")
D.
s=selector.xpath("//book/title[@lang='chinese']/text()")
【判断题】通常可以采用Hinsberg反应来鉴别伯、仲、叔胺。
【单选题】销售产品一批,价款l 0 0 0 0 0 元,增值税1 7 0 0 0 元,货款尚未收回。该笔业务编制 计分录是( ) 。
【单选题】我们要在传承与创新中树立和坚持正确的( )、民族观、国家观、文化观,增强做中国人的骨气和底气。