有关医疗机构使用医疗用毒性药品的说法，正确的是（）

A.每次处方剂量不得超过2日常用量

B.调配毒性药品，应凭医师签名的正式处方，并加盖医疗单位公章

C.对处方注明"生用"的毒性药品，应当付炮制品

D.处方调配后，配方人和复核人员都应当签名

The human beings have polluted the environment seriously. It is time the United Nations must take some measures.

A. take
B. taking
C. to take

D. took