I've tried very hard to improve my English. But by no means  _____ with my progress. 　　[ ]

A. the teacher is not satisfied

B. is the teacher not satisfied　　

C. the teacher is satisfied

D. is the teacher satisfied

恶性贫血（）

A.贮存铁下降，早期出现血清铁蛋白下降

B.贮存铁更进一步减少，铁蛋白减少，血清铁和转铁蛋白饱和度下降，总铁结合力增高和游离原卟啉升高，出现一般症状

C.除上述特点外，尚有明显红细胞和血红蛋白减少，并出现多个系统症状

D.内因子缺乏

E.铁粒幼红细胞增多