sceptic
noun [ C ] UK (US skeptic) uk/ˈskep.tɪk/ us/ˈskep.tɪk/
持怀疑态度的人
a person who doubts the truth or value of an idea or belief
People say it can cure colds, but I'm a bit of a sceptic. 人们说它能治感冒，我有些怀疑。
to convince the sceptics 说服持怀疑态度的人
Synonym: doubter