明确维生素D缺乏性佝偻病早期，应如何治疗

A．口服维生素D500010000U/天，1个月后改为预防量

B．服维生素D10000～20000U/天，1个月后改为预防量

C．多晒太阳，给予预防量口服维生素D

D．口服钙剂即可

E．手术矫正

With so much homework ________, I have to stay at home, giving up the idea of playing computer games with Peter.   

A．to do

B．being done

C．done

D．doing