非常感谢老师们的解答！
非常感谢老师们的解答！
One of the great questions of all time still has scientists taking part in discussions: What happened to the land called Atlantis? Long ago, the ancient Greek philosopher Plato wrote about Atlantis. He said that long before his time it (was) a beautiful land near Europe. Historians believed that it (was) a very rich place with palaces and traditional culture. All of a sudden it disappeared. Ancient people thought it (sank) into the sea. Over time, a number of scientists have tried to look for it. 曹老师：您好！请教上面摘录中，出现的2处(was)，一处(sank)，为什么不使用过去完成时had been, had been, had sunk 呢？ 是否可以使用过去完成时？
Many scientists believe our love of sugar may actually be an addiction. When we eat or drink sugary foods, the sugar enters our blood and influences parts of our brain that make us feel good. Then the good feeling goes away, leaving us wanting more. All tasty foods do this, but sugar has a particularly strong effect. In this way, it is in fact an addictive drug, one that doctors recommend we all cut down on. 曹老师：您好！ 1）这句 parts of our brain that make - 其中定语从句that make是指parts为先行词吧？ 2）这里leaving us wanting more - 为什么是wanting, 而不是to want呢？ 3）这里的All tasty foods do this - 这里的do this怎么理解？是动词的整体替代，不可分割去理解，对吗？ 4）这句it is in fact an addictive drug, one that doctors recommend we all cut down on. 是否等同于 it is in fact an addictive drug, which doctors recommend we all cut down on. 二者含义句式有什么理解上的差别呢？ 谢谢老师。
1 make的复数形式不是已经告诉你了吗？2 现在分词作leave的宾补，分词动作或状态在leave这个动作发生的时候就已经存在着。to do作leave的宾补，不定式的动作在leave的动作结束后才发生。3 do this为动词性替代。替代前面提及的事情。4 one在此为名词替代词，替代a drug, 后接that引导的限制性定语从句修饰one。整体是一个名词性结构作同位语。你改为which从句后，则结构上是一个非限制性定语从句。意思是一样的，但语法结构不同。
Unlike many large schools, which teach acrobatics and kickboxing, Hu teaches his students traditional kung fu forms. He teaches them the way his master—a Shaolin legend—taught him. But attracting new students to this style of kung fu has become a problem. Hu is afraid his art will soon die out. He has to remind his students that kung fu was designed for fighting, not to entertain. "There are no high kicks or acrobatics [here]," he says. "It is hard to convince boys to spend many years learning something that won't make them wealthy or famous." Hu's students have little. They sleep in unheated rooms and train outside no matter what the temperature. They hit trees with their bare hands and take turns sitting on each other's shoulders to build leg strength. Why such hardship? To master kung fu, they must learn respect, and how to "eat bitterness," a Mandarin expression meaning "to endure suffering." The life of a Shaolin master, Hu teaches, is not easy or attractive. 曹老师： 1）Hu's students have little. 意思是没有钱的意思吗？ 2）怎么理解 Why such hardship? 这句话的结构和含义呢？ 谢谢。