‌异质结的超注入现象是指？‍

单项选择题Do you always agree with your teachers? Sometimes you might have a different answer to a math problem__①___your teacher. Or perhaps they could scold (责备) you when you don't think you did anything wrong. What do you do then? A story on yahoo.com says that__②__students are speaking out and even arguing with their__③__ . It's__④__for students to say what they think. In the past,__⑤__Chinese students dared speak back to their teachers. It was an unwritten rule that teachers were_⑥___right. But now students are beginning to think more by themselves and dare to say__⑦__they want. But students should choose the right way to speak out. You should respect teachers. They are older than you and have more__⑧__. So, never use rude words when speaking to them. And don't make them feel bad when you don't__⑨__them. Try to find the right __⑩__to talk to your teacher. For example, discuss the problem after class. ⑧请作答 A、students B、books C、friends D、experience

单项选择题二战后，50年代的马歇尔计划与援助日本的计划，还不是真正意义上国际经济合作，这个时期合作有三个特点，以下叙述错误的是：______ A、政治意义超过经济意义 B、以国际借贷资本的间接流动为主 C、技术要素的流动以援助为主 D、跨国公司大量出现