接班时，检查张紧跑车是否（），拉紧滚筒上的皮带是否跑偏。
A.失爆
B.清洁
C.牢稳
D.漏油
参考答案：C
We went through a period ______ communications were very difficult in the rural areas. [ ]
A. which
B. whose
C. in which
D. with which
结节性甲状腺肿伴甲状腺功能亢进适合的治疗是
A．丙基硫氧嘧啶B．他巴唑C．131I治疗D．甲状腺次全切除E．碘盐治疗
