How long has John _______–For almost eight months.

The father seldom had time to share with his children, because he devoted most of his time _______ research in his lab.

22 Jack, you’ve done your homework, ________ you?

(2014·蚌埠九中模拟)General secretary Xi Jinping urged Washington ________ concrete measures to loosen hightech export controls to China.

He always brings me a pretty gift ____ he comes to visit me.