A:1
B:﹣1
C:−513
D:−135
The streets here are not so ____ as those in our city.
物质的量浓度相同的NaCl MgCl2 AlCl3三种溶液,当溶液的体积比为1:1:1时,三种溶液中Cl﹣的物质的量之比为( )