【单选题】It is______for the interviewee to work until midnight now.
【单选题】It is thus of exceptional importance ______ extinction theories, but until now problems with dating have limited its potential.
A.
for a testing purpose on
B.
as a testing reason in
C.
as a testing ground for
D.
for some useful ends of
【判断题】根据儿童生理特点,儿童期适宜的音域为c1-d2。
【判断题】保证足额安全地收取款项是收款业务控制制度的根本目标( )
【单选题】NPN型三极管放大电路中,若三极管的基极与发射极短路,则下列说法正确的是()