白色盘状南瓜和黄 * * 状南瓜杂交，两对相对性状自由组合，F₁全为白色盘状南瓜。若F₂中纯合白 * * 状南瓜有1000个，从理论上算，F₂中杂合白色盘状南瓜的数目是：[     ]

A．1000

B．2000

C．4000

D．8000

—_____ they are talking to each other!  

—Yes. They are really happy to see each other.       [ ]

A. What excited

B. How excited

C. What excitedly

D. How excitedly