【单选题】某反应的速率常数k=7.7×10-6s-1,又初始浓度为0.2mol•dm-3,则该反应的半衰期为:( )
【单选题】这是著名足球明星马拉多纳,他曾经在世界杯上用手打入一球,裁判没有看清,判进球有效,这个动作事后被称为“上帝之手”。请问马拉多纳是哪个国家的运动员
【单选题】Why can't the woman type the letter?
A.
The typewriter is broken.
C.
The woman didn't have enough time to type it.
【单选题】why can't the woman attend the evening party?
A.
She will go on a business trip.
B.
She has to finish her report.
C.
She will visit her parents.
D.
She has to meet her clients.
【单选题】Why can't the woman eat more?
A.
Because she doesn't like meat pie.
C.
Because she doesn't feel hungry.
D.
Because she wants to lose weight.
【单选题】某反应的速率常数 k = 7.7×10 -4 s -1 ,又初始浓度为 0.1 mol·dm -3 ,则该反应的半衰期为:
【单选题】Why can't the woman get the book from the library?
A.
It wasn't published recently.
B.
It is in great demand.
C.
It was sold out already.
D.
It isn't owned by the library.