The biggest whale is _____ blue whale, which grows to be about 29 meters long—the height of ____ 9-story building.

A．the; the

B．a; a

C．a; the

D．the; a

站在百米赛跑终点的计时员，怎样开始记时才不会影响运动员的成绩？（　　）

A．从听到枪声

B．从看到发令枪的白烟

C．从看到运动员的起跑

D．从看到发令员举起发令枪