下列各句中，没有语病的一句是（ ）

Afghans used to hold big weddings, costing thousands of dollars, in a county _____ the average annual income is less than $400

Tis _____ hisability.

We ____ the task by the time he came to help us.[ ]

Please call me at 8:00 tomorrow morning． I’m kind of forgetful．-Don’t worry about that; you’ll be surely ________．[ ]