17da6da161d12de.png在HTML页面上包含如下创建层的语句，那么编写Javascript语句实现显示该层的语句错误的是（ ）。 A: document.getElementsByTagName(“div”)[0].style.display=”block” ; B: document.getElementById(“imageLayer”).style.display=”block”; C: document.getElementsByName(“imageLayer”).get(0).style.display=”block”; D: document.getElementsByName(“imageLayer”)[0].style.display=”block”;

在HTML页面上包含如下创建层的语句，;;;;;;;那么编写Javascript语句实现显示该层的语句错误的是（ ）。 A: document.getElementByName(“imageLayer”).get(0).style.display=”block”; B: document.getElementById(“imageLayer”).style.display=”block”; C: document.getElementByTagName(“div”)[0].style.display=”block” D: document.getElementByName(“imageLayer”)[0].style.display=”block”;

17da6da0fb551d7.png在HTML页面上包含如下创建层的语句，那么编写Javascript语句实现显示该层的语句不正确的是（ ）。 A: document.getElementByTagName(“div”)[0].style.display=”block” B: document.getElementById(“imageLayer”).style.display=”block”; C: document.getElementByName(“imageLayer”).get(0).style.display=”block”; D: document.getElementByName(“imageLayer”)[0].style.display=”block”;

以下选项中使用伪元素选择符让浮动元素的父元素高度自适应的是 A: 元素:after{content:"";display:block;clear:both} B: 元素:after{content:"";display:block;height:0;clear:both} C: 元素:after{content:"";display:block;clear:both;height:0;overflow:hidden;visibility:hidden} D: 元素:after{display:block;clear:both; height:0;overflow:hidden;visibility:hidden }

【填空题】代码补全: .clearfix:after { content: ""; display: block; height: 0; clear: (); visibility: hidden; }

创建内部块的命令是（）；创建外部块的命令是（）。 A: Block;Insert; B: WBlock;Block; C: Block;Block; D: Block；Wblock;

创建内部块的命令是（ ）；创建外部块的命令是（ ） A: Block；Wblock; B: Wblock;Block； C: Block; Block; D: Block; Insert；

A snatch block is a（）. A: block used only with manila rope B: chock roller C: hinged block D: strong block used for short，sharp pull

What are forms of business letters? A: Full Block Form B: Modified Block Form with Indented Style C: Modified Block Form D: Simplied Block Form

Block A has mass 1.00 kg and block B has mass 3.00 kg. The blocks collide and stick together on a level, frictionless surface.After the collision, the kinetic energy (KE) of block A is A: 1/9 the KE of block B B: 1/3 the KE of block B C: 3 times the KE of block B D: 9 times the KE of block B E: the same as the KE of block B