Studies show that people are more __________ to suffer from back problems if they always sit before computer screens for long hours.

A．likely

B．possible

C．probable

D．sure

结缔组织痣患者可合并下列症状，其中不包括（）

A.脱发

B.白癜风样痣

C.色素痣

D.疣状痣样皮损

E.血管瘤