词汇。

根据下面句子的意思及所给的汉语提示，写出空缺处的单词或词组的正确形式。

1. The girl is doing an ________(实验).

2. My cat ________(和……玩)me when I come home from school every day.

3. We are _______(准备好的)for the exam.

4. She looks very pretty _______(戴上那顶帽子).

5. He _______(睡着)while he was doing his homework.

偶然误差的绝对值相等的正负误差出现概率相等。