【单选题】听力原文: Recent research has claimed that an excess of positive ions in the air can have an ill-effect on people's physical or psychological health. What are positive ions? Well, the air is full of ions,...
【单选题】世界卫生组织推荐的人类食用油脂肪酸标准为: 饱和脂肪酸∶单不饱和脂肪酸∶多不饱和脂肪酸=1∶1∶1(物质的量之比),下列选项中按饱和脂肪酸、单不饱和脂肪酸、多不饱和脂肪酸顺序排列的是( ) ①C 17 H 35 COOH;②C 17 H 33 COOH;③C 15 H 31 COOH;④C 17 H 31 COOH;⑤C 17 H 29 COOH
【简答题】阅读理解。 Recent research has claimed that an excess of positive ions in the air can have an ill effect on people's physical or psychological health. What are positive ions? Well, the air is full of ions,...
【简答题】A wave of recent research has pointed to the risks of over praising a child. And it seems that how to draw a line between too little praise and too much has become a high-pressure _ _ act for parents....