He is recognized as the authority of that project.

I sent him three letters.

The phone call with him was very enjoyable.

I don't have time to talk on the phone with him.

I often make three phone calls with him in a day.

The annual sales increased by 5% compared to the previous year.

Recently, my lumbago has been so bad that I can't concentrate on my work.

Japan and China are strengthening their foreign commerce relationship.

We are engaged in international trade with America.

I've had a toothache since last night and couldn't sleep.