In that school, English is compulsory for all students, but French and Russia are ____.

                                                                                                                                    [ ]

A. special

B. optional

C. regional

D. original

诊断甲状腺功能亢进症最灵敏可靠的实验室检查方法为（）

A.基础代谢率

B.血清蛋白结合碘

C.测TGA TMA

D.测TT3、TT4、FT3、FT4

E.甲状腺摄131I率