【多选题】According to the speaker, what are the best descriptions of normal lectures at school?
B.
Interesting and rewarding.
【单选题】*在测定中和热的实验过程中,碱储液管漏液可能会出现的实验现象是
【单选题】What is the color code of the shelves where normal size novels are placed?
【单选题】根据阀瓣前后的压力差自动启闭,有严格的方向性,只许介质向一个方向流动,可阻止其逆向流动的阀门是( )。