硫胺素缺乏可引起()维生素A缺乏可引起()维生素PP缺乏可引起()
A．坏血病
B．癞皮病
C．脚气病
D．夜盲症
E．佝偻病
参考答案：C,D,B
Each individual expresses his opinion in the group by where he stands when a lot of people ______ together in a chat.
A．squeeze B．stick C．pad D．cluster
