简述布匿战争。
You create a Web page that contains the following code. You need to ensure that when the user clicks an item in the list， the text color of the "Welcome!" message will change. Which declaration should you use？（） ["<ul id="color"> <li onclick="changeColor(this.innerText);">Black<\/li> <li onclick="changeColor(this.innerText);">Red<\/li> <\/ul> ","<ul id="color"> <li onclick="changeColor(this.style.color);">Black<\/li> <li onclick="changeColor(this.style.color);">Red<\/li> <\/ul> ","<ul id="color"> <li><a onfocus="changeColor(this.innerText);">Red<\/a><\/li> <li><a onfocus="changeColor(this.innerText);">Black<\/a><\/li> <\/ul> ","<ul id="color"> <li><a onfocus="changeColor(this.innerText);">Red<\/a><\/li> <li><a onfocus="changeColor(this.innerText);">Black<\/a><\/li> <\/ul>"]
下列各项中，属于加剧产业竞争的主要因素有（）。 ["竞争对手时常更换","产业已进入成熟期","产业进入障碍低而退出障碍高","企业拥有稀缺资源"]
（）是企业研究与开发能力的基石。
You are developing an application that uses role-based security. The prinicipal policy of the application domain is configured during startup with the following code：AppDomain.CurrentDomain.SetPrincipalPolicy（PrincipalPolicy.WindowsPrincipal）； You need to restrict access to one of the methods in your application so that only members of the local Administrators group can call the method. Which attribute should you place on the method？（） [" [PrincipalPermission （SecurityAction.Demand， Name = @"BUILTIN\\Administrators"）]"," [PrincipalPermission （SecurityAction.Demand， Role = @"BUILTIN\\Administrators"）]"," [PrincipalPermission （SecurityAction.Assert， Name = @"BUILTIN\\Administrators"）]"," [PrincipalPermission （SecurityAction.Assert， Role = @"BUILTIN\\Administrators"）]"]
阻塞高压
