首次一举完成穿越东西、南北半球的航行壮举的航海家是（　　）

A．哥伦布

B．郑和

C．菲利普斯

D．麦哲伦

——Do you know_____?

——He is a dentist.

A．where he is from

B．where is he from

C．what does his father do

D．what his father is