摘要： -Which is more useful, biology or chemistry? A. Either of B. None of C. Both of D. All of
网址：http://m.1010jiajiao.com/timu3_id_2375417[举报]
--Which is more useful, chemistry or biology?
--I think _____ them are useful.
[ ]
|
A ．none of |
B ．all of |
|
C ．either of |
D ．both of |