以昆虫为媒介而传播的疾病是（）

A.斑疹伤寒

B.戊型肝炎

C.艾滋病

D.流行性出血热

E.结核病

_______ is known to us all is that the theme of Shanghai World Expo is “Better City, Better Life”.

A．It

B．That

C．Which

D．What