下列计算错误的是[ ]
A.(-7)+(+5)=-2
B.(-7)-(-5)=-2
C.(-7)×(-5)=35
D.(-7)+(-5)=-2
答案:D
无色透明溶液中放入铝片,产生大量氢气,该溶液中肯定可以大量存在的离子是
A.Fe2+、K+、Cl-、NO3-
B.Na+、K+、CO32-、Cl-
C.Na+、Al3+、NO3-、SO42-
D.K+、Na+、Cl-、Br-
Jim, how nice your car is! How long ________ you _________ it? [ ]
A. did; buy
B. did; have
C. have; had