三角形的内角分别为55°和65°,不可能是这个三角形外角的是[ ]
A.115°
B.120°
C.125°
D.130°
答案:D
下列反应的离子方程式正确的是
A.氨气通人盐酸中:H++Cl-+NH3=NH4Cl
B.盐酸滴到铜片上:Cu2++2H+=Cu2++H2↑
C.碳酸钡溶于醋酸:BaCO3+2H+=Ba2++H2O+CO2↑
D.澄清的石灰水跟盐酸反应:H++OH-=H2O
—Is this your sister?
—_____. [ ]
A. Yes, that is
B. No, it isn't
C. Yes, this is
D. No. that isn't