■平均每天有10個學生缺席。

誤：An average of 10 students was absent each day.

正：An average of 10 students were absent each day.

析：“an average of＋復數名詞”作主語，謂語用復數，而“the average of＋復數名詞”作主語，謂語通常用單數。如：The average of these numbers is 50.(這些數的平均數是50)。

■我們平均每天收到10封信。

誤：In (the) average we receive ten letters each day.

正：On (the) average we receive ten letters each day.

析：on (the) average(平均)是固定短語，不用介詞 in。

■昨天的平均氣溫是多少?

誤：What was the temperature of average yesterday?

正：What was the average temperature yesterday?

析：average 可用作形容詞(意為“平均的”)直接放在名詞前作定語。又如：The average age of the boys in this class is fifteen. (這個班男生的平均年齡為15歲)。