将SO₂和SO₃两种气体分别通入BaCl₂溶液，其结果是（   ）

A．两种气体都生成BaSO₄沉淀

B．只有SO₃会生成BaSO₄沉淀，SO₂通入溶液中无沉淀生成

C．分别生成BaSO₃和BaSO₄两种沉淀

D．都不生成沉淀

The information regarding ports such as buoyed channels,fairway,location and number of terminals,river channels,details of navigational marks,location of overhead bridges, underground cables etc. are shown in（）

A.small-scale charts

B.medium-scale charts

C.large-scale charts

D.natural scale charts