—Excuse me, Mum. When can we have dinner?—Not until it in half an hour.
A:is prepared
B:has been prepared
C:will be prepared
D:was prepared
请对他们的观点进行辨析。
①癌细胞的扩散
②蝌蚪发育成为青蛙的过程中尾部消失了
③寄主细胞因病毒的复制、释放而消亡
④被病原体侵染的细胞的清除