but they have less improved in spelling, and even have a little decreased in oral english, which may be mainly caused by those students' improper attitude, behavior and instant motivation.
这主要是由于学生的自主学习态度、行为和动机持续不长等因素造成的。
conclusion the acne in adolescent female patients may be mainly caused by the less secretion of the estrogen which lead to rising the serum levels of the testosterone relatively.
结论青春期女性痤疮患者发病的主要原因可能是由于雌激素分泌不足,使血清内睪酮水平相对增多所致。
the wheel flange wear is caused by the flange action of the wheel and rail, whereas the double-groove wear on tread may be mainly caused by the break shoe.
轮缘磨耗主要是轮轨相互作用的结果,而踏面上的凹槽磨耗可能主要由闸瓦制动引起。