A.+→
B.→+
C.+→
D.→+
答案:D
This is the second time that we _____Guilin, whose beautiful scenery attracts a large number of tourists
every year.[ ]
A. have visited
B. visited
C. had visited
D. will visit
下列物质能在pH为13的水溶液中大量共存的是
A.KOH、Na2SO4、MgCl2
B.NaCl、Na2CO3、NaNO3
C.FeCl3、HCl、NaOH
D.CaCl2、NaCl、 K2CO3