I ______________ think so. [ ]
A. don't
B. does
C. Did
答案:A
Graves病时,血清激素水平变化中正确的是()
A.T3↑、114↑、TSH↓
B.T3↑、TT4↑、TSH↑
C.TT3↓、TT4↓、TSH↑
D.TT3↑、FT4↑、TSH↑
E.TT3↓、反T3↓、TSH↓
简述如何按阀门的公称压力区分阀门的种类?