It was my sister ________ first had the idea to cycle along the entire Mekong River. A. who B. whom C. /
测定硫酸铜晶体中含结晶水含量的实验，造成结果偏高的原因是（ ） ①坩埚用水洗后没有烘干；②加热时有少量晶体溅出；③把加热得到的白色粉末
Following the guide, we went into a house,_______ wall hung a picture of Einstein. A . on its B. on that C. on whose D.
①廿二日天稍和，偕数友出东直，至满井。②高柳夹堤，土膏微润，一望空阔，若脱笼之鹄。③于时冰皮始解，波色乍明，鳞浪层层，清澈见底，晶晶
From my experience, there are three main reasons why people don’t cook more often: ability, money and time, ___36．_Money is a topic I’ll save for another day. So today I want to give you some
化学与生产和生活密切相关。下列过程中没有发生化学变化的是 （ ） A．氯气作水杀菌消毒剂 B．硅胶作袋装食品的干燥剂 C．二氧化硫
Cu2O是一种红色的固体，不溶于水，在酸性溶液（硝酸除外）中，可发生反应生成Cu2+和Cu．请回答下列问题： （1）Cu2O中铜元素的化合价为 ． （2）将一
