How late was the flight from Bangkok?
A．Two hours.
B．One hour.
C．Half an hour.

原子吸收光谱法测定钙时磷酸根有干扰，为消除其干扰，可采取的措施( )。(1)加入铝盐，(2)加入锶盐，(3)加入EDTA，(4)使用N2O-C2H2火焰

A.(1)、(2)、(3)
B．(1)、(2)、(3)、(4)
C．(2)、(3)、(4)
D．(2)、(4)

点击查看答案

听力原文：M: I've just brought your ladder back. Thanks for lending it to me. Where shall I leave it?W: Just lean it against the wall there. Use the ladder again any time.Q: What's the probable relationship between these two speakers?(2)A．Relatives.B．Neighbors.C．Roommates.

A.
Q:
B.Relatives.
B．Neighbors.
C．Roommates.

点击查看答案