---Are you still busy?---Yes, I ____ my work, and it won’t take long.

A．just finish

B．am just finishing

C．have just finished

D．am just going to finish.

关于鸡卵的结构叙述错误的是（　　）

A．受精卵的胚盘将来发育成雏鸡

B．在母鸡体内受精卵开始发育

C．卵黄和卵白都为胚胎提供主要营养

D．煮鸡蛋时有气泡冒出，说明卵壳上气孔