单项选择题
Cycling is a good exercise.（）, it doesn't pollute the air.
A.Therefore B.Moreover C.But D.However
单项选择题 Speed limits should lead（） fewer deaths on the roads.
单项选择题 The hospital is carrying（）tests to find out what’s wrong with her.
单项选择题 Hello, I’m Harry Potter. Hello, my name is Charles Green, but（）.
