[解析]
(1)D.细节理解题。根据第一段For example,it is ridiculous that we blame young people for being addicted to their apps when the simple truth is that they are designed to be addictive.In the world of apps,addiction is what brings in money.例如,当简单的事实是他们被设计成会上瘾时,我们就责怪年轻人沉迷于他们的应用程序是可笑的。在应用程序世界中,成瘾才是赚钱的原因。可知,科技公司应为成瘾而负责。故选D.
(2)B.细节理解题。根据第二段Whether you run a video service,a news site or a mobile game,certainly your product will have an effect on the mental health of your users﹣negative or positive.But the sad reality is that if you are not optimizing that effect,it tends to be former.无论您是运行视频服务,新闻网站还是手机游戏,都肯定会对您的用户的心理健康产生负面或正面的影响。但是可悲的现实是,如果您没有优化该效果,那么它往往是前者。可知,如果使用者没有改善幸福感,往往会变得悲观。所以划线词的意思是"改善"。A.explaining解释;B.improving改善;C.discovering发现;D.admitting承认。故选B.
(3)C.细节理解题。根据第四段 Notifications can be made friendlier by not showing them in real time.通过不实时显示通知,可以使通知更加友好。可知,应用程序通过减少通知的醒目性降低作者的负面影响。故选C.
(4)A.态度推断题.根据最后一段When a company becomes more well﹣being﹣positive,they add a competitive difference and become more attractive.当一家公司变得更积极时,它们就会增加竞争差异并变得更具吸引力。可知,作者认为积极的公司将最终受益。故选A.