She is working on the problem.

He is working on a new novel.

He is working on the new plan.

He is busy with the final draft.

He has been working on a new book for two months.

Party leaders are grappling with flaws in the party system.

Sooner or later, we'll have to tackle the problem in earnest.

I am working on my new book.

Because the new trainee did things sluggishly, he was told that he'd be fired if he didn't start taking his job seriously.

We must get down to our homework.

I have to bone up on my physics.

I have an important business to attend to in my office.

He had been working on his novel for six months when we visited him.

The whole nation is waging a war against poverty.

The company went after its no. 1 customer complaint: power outages.

It's time to work now. Let's get down to business.

To begin with, we must tackle the problem.

The composer is wrestling with the new music.

The writer is working on a new book.

The writer is tackling the now new novel.