Ⅰ.单句语法填空
1．The famous player tried again and again after each failure. That is ________ he succeeded at last.
why [句意：每次失败后，这位著名的球员一次又一次地尝试。那就是为什么他最终成功了(的原因)。is后面是一个表语从句，用why引导从句，表示结果，故填why。]
2．The retired engineer is showing ________ the wheelchair climbs stairs, which all the curious visitors want to know.
how [句意：这位退休的工程师正在展示轮椅如何爬楼梯，这是所有有好奇心的游客想知道的。由句意可知，填how，意为“怎么，如何”。这是how引导的宾语从句。]
3．Dick enjoys painting but he knows the fact ________ he doesn't have what it takes to be a professional.
that [句意：迪克喜欢画画，但他知道自己没有成为一名专业画家所需要的(素质)。that引导同位语从句，说明fact的具体内容。]
