or接一段時(shí)間的省略問題
一、當(dāng)for引導(dǎo)的時(shí)間短語用來修飾具有靜態(tài)意義的動(dòng)詞是常常可以省略。如：
They lived in China (for) seven years.
The meeting lasted (for) two hours.
They will be in Chicago (for) a year.
二、當(dāng)for與all開頭的名詞短語連用時(shí)，必須省略for.
She’s been lying in bed all day.
三、當(dāng)for短語修飾動(dòng)態(tài)動(dòng)詞時(shí)或者用于否定句是，則借此for不能省略。
I’m going away for a few days.
I haven’t seen him for three weeks.
四、當(dāng)for用在句子開頭時(shí)，一般也不能省略。請(qǐng)比較：
a. He lived abroad (for) six years.
For six years, he lived abroad.
b. He waited anxiously at hospital (for) some time.
For some time, he waited anxiously at hospital.