This is not my watch. Do you know _____ it is?[ ]
A. what
B. which
C. who
D. whose
答案:D
能用来分离Fe3+和Al3+离子的试剂是
A.KSCN
B.NH3· H2O
C.NaOH溶液
D.H2S溶液
Though there are some differences in American education and Chinese education, both systems are _____
excellent graduates.
[ ]
A. turning out
B. turning away
C. turning off
D. turning in