Wang Ping hesitated for ___ before he ___ to the question.

The incomes of skilled workers went up. ______， unskilled workers saw their earnings fall.

You needn’t have apologized for your absence—       , it’s hardly your fault.

 He absorbed himself so entirely to his research that ____he made himself ill.

—— Excuse me, is this Mr. Brown’s office? —— I’m sorry, but Mr. Brown＿＿＿works here.He left about three weeks ago.