doubtfully

“I’m trying to bring out as many features of the landscape as I possibly can, and shadows hide features,” he tells me, gazing up doubtfully.

“I guess we could ask Mr. Poe about it,” Violet said doubtfully, as Klaus stood beside her and dried the dishes.

If the proprietor signals for you to come back, turn around doubtfully and slowly walk back a few steps to see if she is serious.

“I suppose I could look for it in the morning,” she replies doubtfully.

I looked at him doubtfully: thin and drawn, with thighs and arms so puny that no muscle showed even when he flexed them.