They _______ all the details of the plan time and again to make sure that the project went smoothly.

With economy developing at great speed, our city has _____ quite a few changes in recent years.

When the dog attacked me, I _________ myself with a stick.

Yesterday, I came across my former classmate, but his name ________ me, which made me embarrassed.

—It seems that you know Dr. John very well. —Of course, we   ________     together for five years in the 1990s.