复数： experimenters

The experimenter watched the proceedings from across the table .

实验者在桌子另一边观看整个过程。

Another person in the room beside the experimenter said he saw the participant hitting the alt key .

除了实验者以外在屋子里的另一个人说他看到参加者按了alt键了。

The task was boring and still is boring whatever the experimenter tells me .

无论实验者告诉我什么，这个任务始终都是无聊的。

Were the infants simply getting excited by the experimenter ?

婴儿是不是单纯因为实验者而感到兴奋？

And when the experimenter stuck his tongue out , infants stuck theirs out .

实验者吐舌头的时候，婴儿才吐舌头。