碘缺乏对健康影响除了甲状腺肿大外，还可引起（）
A.肝脏损害
B.免疫功能低下
C.发育障碍
D.内分泌紊乱
E.骨代谢障碍
参考答案：C
如图所示，当开关______和______断开，______闭合时，L1、L2组成串联电路；当开关______断开，______和______闭合时，L1、L2组成并联电路．
With all the problems ______, the manager went home and had a good rest.
A．solved
B．to solve
C．solve
D．solving
