His intellect and mental agility have never been in doubt.他的才智和机敏从未受到怀疑。When in doubt, call the doctor.如有疑问，请联系医生。The outcome was still in doubt.结果仍不确定。...

in doubt的音标：in doubt的英式发音音标为：[in daut]in doubt的美式发音音标为：[ɪn daʊt]...

存在疑问，大成问题...