已知等差数列$\left\{a_n\right\}$的前$n$项和为$S_n$，且$S_{200}=100$，$A,B,C$为平面内三点，点$O$为平面外任意一点，若$\overrightarrow{OB}=a_{100}\overrightarrow{OA}+a_{101}\overrightarrow{OC}$，则$A,B,C$（　　）

近年来，我国逐步建立农产品目标价格制度，在市场价格高于目标价格时财政补贴低收入消费者，低于目标价格时按差价财政补贴生产者。这一制度的实施是基于（    ）

①价值规律调节着生产和生活消费   

②资源配置可通过行政手段得以实现

③利益杠杆能引导市场主体的活动   

④分配对生产和消费有着重要的影响

铝在氧气中燃烧生成氧化铝。在这个反应中，铝、氧气、氧化铝的质量比是 （   ）                

单词拼写：根据短文内容和所给中文提示，在空白处写出单词的正确形式。每空限填一词。

    Tu Youyou, 84, is the woman who uses sweet wormwood's (青蒿)  special power to help millions of lives. Now she is ____ (广泛地) well-known as the winner of the 2015 Nobel Prize in Physiology or Medicine. We Chinese people take ____ (骄傲) in her.

    When Tu began her____ (医疗的) research in the 1960s, things were hard. They had neither modern machines ____ (也不) lots of money. But those didn't  ____ (阻止) her at all. She ____ (失败) many times, but she never gave up. And she even used to test medicine ____（通过）eating them herself. Tu was always busy with her work so she ____ (很少) stayed with her family. You can't imagine ____ (多么) hard her job was! Finally, Tu found artemisinin (青蒿素) in 1971. During the next few years, she made an effort to improve the medicine.

    According to World Health Organization, about 200 million people were  ____ (挽救) with the help of artemisinin. “I feel happy when I see patients become healthy again.” she said.