——Did you find the missing couple in the mountain yesterday?

——No, but we _____ to get in touch with them ever since.

A．have tried

B．have been trying

C．had tried

D．had been trying

患儿男，58天。34周早产，生后用婴儿奶粉喂养，食欲佳，化验检查：血红蛋白100g/L，红细胞数2.8×10⁹/L，白细胞数7×10⁹/L。该婴儿可能的诊断是（）。

A.感染性贫血

B.生理性贫血

C.营养性缺铁性贫血

D.营养性巨幼细胞贫血

E.再生障碍性贫血