【单选题】He gave us another piece of advice, _____ of great help to the research work. [ ]
【判断题】婴幼儿情绪外露的特点,不利于成人与儿童间良好的沟通
【单选题】Edison was a great inventor. He ______ to inventing things. [ ]
【单选题】下列选项中()是指金属材料在无限多次交变载荷作用下不至于发生断裂的最大应力。
【单选题】He gave a great performance, but he was very_________.