安德鲁·法尔和克雷格·梅洛因发现了“RNA干扰机制——双链RNA沉默基因”而获得诺贝尔生理学或医学奖。它指的是反义RNA与靶 mRNA形成的互补的双链RNA
细胞分化是生物体普遍存在的一种生命现象,下列叙述中不正确的是 A.分化发生在生物体的整个生命进程中 B.分化是基因在特定时间和空间条件
下列说法正确的是( ) A.测定空气中氧气含量时,不需检查装置的气密性 B.测定空气中氧气含量时,红磷熄灭马上打开止水夹
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