骨髓移植的适应证为（）

A.急性白血病

B.慢性粒细胞白血病

C.恶性淋巴瘤

D.重型再生障碍性贫血

E.多发性骨髓瘤

One third of the people trapped in the ruins _______ at last.

A．has dug out

B．was dug out

C．have dug out

D．were dug out