下列哪种人群比较容易发生缺铁（）
A.育龄妇女
B.生长发育时期儿童
C.青少年
D.成年人
E.胃及十二指肠疾病患者
参考答案：A, B, E
I feel upset, for there are so many, troublesome problems _____ . [ ]
A. remaining to settle
B. remained to settle
C. remaining to be settled
D. remained to be settled
INMARSAT-C站发遇险报警有（）种方法
A.1
B.2
C.3
D.4
