---You could have walked here.---Yes. A taxi ___________ necessary.

 ---- _____either you or he to go there?  ---- _____is.

—I called you at 5:00 yesterday afternoon, but no one answered.—Sorry, I with my parents ________ at that time.

Mary is one of the brightest students who_________ from New York University.

Mr. White as well as his friends ________ a number of countries in the past few years.