Greater demands were being placed on the police by growing violence and left and right-wing extremism. 不断增加的暴行和左翼右翼极端主义使得需要更多警力。老师：您好！这句话我没理解（1）为啥这里要用were being placed on 这个时态（2）我没理解这个...
This is not because a person arrives his natural limit of efficiency when he reaches the sixth grade,for it has been shown againand again that with special tuition so many older children,and also adults,can make enormous improvement.
...lack of 前面可用介词 for, because of, through 等介词，如：
The plants died through lack of water. 由于缺水那些植物枯死了。
I can’t buy it because of my lack of money. 我不能买它是因为没钱。
Thetheatre has had to close for lack of support. 这家剧院...
Think this through very carefully before you write so that what you say shows a natural progressive from past experience tothe job you are applying for.
...时我在吃午饭，请告诉他等一会儿。译：If he comes during the time I'm having lunch, please tell him to wait a moment. 请教老师，以上的中译英句子正确吗？请您更正。除此之外，您有更好的译法吗(并稍加说明一下)？谢谢老师。