How I _______ I could live on the moon. [ ]
A. think
B. hope
C. want
D. wish
答案:D
只用一种试剂可区别Na2SO4、AlCl3、NH4Cl、CuSO4四种溶液,这种试剂是( )
A.HCl
B.BaCl2
C.AgNO3
D.NaOH
哺乳类的神经系统和感官有何特征?