doubtfully
adv. 怀疑地；含糊地
例句
Keeton shook his head doubtfully.
基顿将信将疑地摇了摇头。
《柯林斯英汉双解大词典》
"It's worth trying," they said doubtfully.
“这值得一试。”他们迟疑地说。
"I think I knew them," said Michael rather doubtfully.
“我想我认识他们。”迈克尔不太确定地说。
