题目

第三次科技革命其主要标志是电子计算机、原子能和空间科学技术的发明和应用，人类从此进入了电气时代。 答案：×(2007·浙江) Many of them turned a deaf ear to his advice, ________they knew it to be valuable. [　　] A．as ifB．now that C．even thoughD．so that