判断题 An exercise with heterogeneity can also have a positive effect on learner attitude and motivation. It provides an opportunity for the teacher to give slower or less confident students the approval and encouragement they need.（）

判断题 An exercise with heterogeneity gives no opportunity for the really advanced students to exercise their capacity.（）

判断题 Verbal presentation of new words means that the meaning of a second language word is demonstrated through concrete objects, visual aids, or through mime and acting.（）