脊髓的主要功能 [ ]
A.反射和传导
B.感觉和运动
C.产生兴奋和传导兴奋
D.产生神经冲动
答案:A
点燃Wg硫粉与足量空气发生化学反应,Wg硫粉完全反应,则参加反应的硫粉与氧气的质量比是( )
A.1:1
B.2:l
C.W:32
D.32:16
Whenever we were ___, he is always ready to ___ us some help.
A.in the trouble; give
B.in trouble; offer
C.in a trouble; pay
D.in trouble,take