练习一

I have had breakfast (just)

Ihave just had breakfast.

He has been in prison (for six months)

Hehas been in prison for six months.

The police have not caught the thief.

Thepolice have not caught the thief yet.

You have asked that question three times. (already)

Youhave already asked that question three times.

Have you been to London (ever)

Haveyou ever been to London?

I haven't seen George. (recently)

Ihaven't seen George recently.

练习二

The bell is ringing.

The bell has just rung.

He is leaving the house

He has just left the house

He is having breakfast.

He has just had breakfast

She is writing a letter.

She has just written a letter.

My sister is turning on the radio

My sister has just turned on the radio

My mother is making the bed.

My mother has just made the bed

She is buying a new hat.

She has just bought a new hat.