【单选题】During working of an air compressor, _____ should be drained .
【单选题】Jane’s brother’s _______ an American company. [ ]
【单选题】为6个月以后婴儿创设运动空间,可以使( )得到充分的发展.
【多选题】为患者进行大量不保留灌肠时,下列哪些是正确的?()
【单选题】苯丙氨酸( )有多种同分异构体。其中同时符合下列两个条件:①有带两个取代基的苯环;②有一个硝基直接连接在苯环上的异构体有 [ ]
【单选题】分子式与苯丙氨酸 相同,且同时符合下列两个条件:①含有两个取代基的苯环②有一个硝基直接连在苯环上,这样的同分异构体数目有
【单选题】From the research conducted by the communication provider Inter-Tel, we learn that______.
A.
attitudes toward IT technology have changed
B.
more employees work to full capacity at home
C.
more businesses have adopted remote working solution
D.
employees show a growing interest in small businesses
【单选题】苯环是指()
C.
1900~1650cm -1 ;1300~1000cm -1
D.
3750~3000cm -1 ;1300~1000cm -1
E.
3300~3000cm -1 ;1675~1500cm -1 ;1000~650cm -1