【单选题】
下列样式定义字体间距为0.5倍间距、水平左对齐、垂直顶端对齐、有下划线，正确的定义是：（ ）
①
p{text-decoration：underline；letter-spacing：0.5em；vertical-align：top；text-align：left；}
②
p{text-decoration：0.5em；letter-spacing：underline；vertical-align：top；text-align：left；}
③
p{text-decoration：left；letter-spacing：top；vertical-align：0.5em；text-align：underline；}
④
p{text-decoration：underline；letter-spacing：0.5em；vertical-align：left；text-align：top；}
【单选题】
下列样式定义字体间距为0.5倍间距、水平左对齐、垂直顶端对齐、有下划线，正确的定义是：( )
①
p{text-decoration：underline；letter-spacing：0.5em；vertical-align：top；text-align：left；}
②
p{text-decoration：0.5em；letter-spacing：underline；vertical-align：top；text-align：left；}
③
p{text-decoration：left；letter-spacing：top；vertical-align：0.5em；text-align：underline；}
④
p{text-decoration：underline；letter-spacing：0.5em；vertical-align：left；text-align：top；}
【单选题】
点击某个设置了超链接的文字，希望在当前网页所在的页面中打开网页，目标选项应设置为（ ）。
①
A. _blank
②
B. _self
③
C. _http
④
D. _URL
【单选题】
设A,B为两随机事件，且A<img class=jc-formula data-tex=\supset src=https://huaweicloudobs.ahjxjy.cn/37A4B3C430EFA04CF480D02C0DFECE89.png style=vertical-align: middle; width: 20px; height: 17px; width=20 height=17/>B，则下列式子正确的是
①
P(A<img class=jc-formula data-tex=\cup src=https://huaweicloudobs.ahjxjy.cn/9BD598E68F21E65385221B2250659C3A.png style=vertical-align: middle; width: 22px; height: 14px; width=22 height=14/>B) = P(A)
②
P(AB)=P(A)<img width=99 height=21 src=http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/spacer.gif word_img=file:///C:/Users/ADMINI~1/AppData/Local/Temp/msohtmlclip1/01/clip_image002.gif style=background:url(http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/word.gif) no-repeat center center;border:1px solid #ddd/>
③
P(B|A)=P(B)
④
P(B-A)=P(B)-P(A)<img width=76 height=21 src=http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/spacer.gif word_img=file:///C:/Users/ADMINI~1/AppData/Local/Temp/msohtmlclip1/01/clip_image002.gif style=background:url(http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/word.gif) no-repeat center center;border:1px solid #ddd/><img width=83 height=21 src=http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/spacer.gif word_img=file:///C:/Users/ADMINI~1/AppData/Local/Temp/msohtmlclip1/01/clip_image004.gif style=background:url(http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/word.gif) no-repeat center center;border:1px solid #ddd/><img width=76 height=21 src=http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/spacer.gif word_img=file:///C:/Users/ADMINI~1/AppData/Local/Temp/msohtmlclip1/01/clip_image002.gif style=background:url(http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/word.gif) no-repeat center center;border:1px solid #ddd/><img width=83 height=21 src=http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/spacer.gif word_img=file:///C:/Users/ADMINI~1/AppData/Local/Temp/msohtmlclip1/01/clip_image004.gif style=background:url(http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/word.gif) no-repeat center center;border:1px solid #ddd/><img width=76 height=21 src=http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/spacer.gif word_img=file:///C:/Users/ADMINI~1/AppData/Local/Temp/msohtmlclip1/01/clip_image002.gif style=background:url(http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/word.gif) no-repeat center center;border:1px solid #ddd/><img width=83 height=21 src=http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/spacer.gif word_img=file:///C:/Users/ADMINI~1/AppData/Local/Temp/msohtmlclip1/01/clip_image004.gif style=background:url(http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/word.gif) no-repeat center center;border:1px solid #ddd/><img width=76 height=21 src=http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/spacer.gif word_img=file:///C:/Users/ADMINI~1/AppData/Local/Temp/msohtmlclip1/01/clip_image002.gif style=background:url(http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/word.gif) no-repeat center center;border:1px solid #ddd/><img width=83 height=21 src=http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/spacer.gif word_img=file:///C:/Users/ADMINI~1/AppData/Local/Temp/msohtmlclip1/01/clip_image004.gif style=background:url(http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/word.gif) no-repeat center center;border:1px solid #ddd/><img width=76 height=21 src=http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/spacer.gif word_img=file:///C:/Users/ADMINI~1/AppData/Local/Temp/msohtmlclip1/01/clip_image002.gif style=background:url(http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/word.gif) no-repeat center center;border:1px solid #ddd/><img width=83 height=21 src=http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/spacer.gif word_img=file:///C:/Users/ADMINI~1/AppData/Local/Temp/msohtmlclip1/01/clip_image004.gif style=background:url(http://www.ahjxjy.cn/design/html/js/vender/ueditor/themes/default/images/word.gif) no-repeat center center;border:1px solid #ddd/>