译为：他们在这件事上并不信任你!
seem to be doingsth表示不定式的动作和主句中seem是同一个时态,比如,He seems to be doing his homework. 他好像正在做作业；
seemtodo 表示不定式的动作发生在主句动词seem之后,比如It seems to rain. 好像要下雨了. rain的动作,是发生在seem之后的；
seemtohavedone sth表示不定式的动作发生在主句动词seem之前,比如 she seems to have finished her homework. 她好像做完了她的家庭作业.finish的动作发生在seem之前