FeCl₃溶液和Fe(OH)₃胶体具有的共同性质是

A．滴人盐酸，先产生沉淀，然后沉淀又溶解

B．都能透过半透膜

C．都有丁达尔现象

D．加热蒸干灼烧，最终都有Fe₂O₃生成

Which vessel is NOT to be regarded as restricted in her ability to maneuver?（）.

A.A vessel transferring provisions while underway

B.A pushing vessel and a vessel being pushed when connected in a composite unit

C.A vessel servicing a navigation mark

D.A vessel launching aircraft