Complete the following sentence with a (compound) word derived from the one(s) given in bracket.
The obvious sign of his （ ） is that he keeps glancing at his watch. (nervous)
【正确答案】：NERVOUSNESS
【题目解析】：
本题考查的是常见形容词的名词形式。
由his和is可知，空缺处应填名词，nervous的名词形式是nervousness意为“紧张、不安”。
句意：他神情不安的明显标志是他总是看自己的手表。