【单选题】(Unit 3B) Never________ in things of which you have no knowledge.
【判断题】在非电子节气门系统中,节气门位置传感器用来检测节气门开度,以反映发动机的不同工况。()
【判断题】处于南半球的国家都是发展中国家,因此发展中国家又叫南方国家。
【单选题】(Unit 3B) It occurs to them that they can buy a sofa that_________into a bed.
【单选题】(Unit 3B) He was too weak to pass the ___ long-distance running in physical test.
【简答题】(2a+3b)(2a﹣3b)+(a﹣3b) 2 ,其中 .