use water to put out the fire if oil catches fire. As is known, oil ________ float on water.

Who is the man giving the speech— Well, if you ________ know, his name is Lyric.

Be calm, Madam, can you remember _____ you had your mobile phone stolen? [ ]

_____ we have got the chance, we’d better make full use of it[ ]

He didn’t make________clear when and where the meeting would be held. [ ]