The old man never feels withhis pet dog around though he lives in an old flat.

Nowhere in nature is aluminium (铝) found free, owing to (由于) its always____with other elements (元素) most commonly with oxygen.[ ]

You may have one of these；in other words，you may have ________you choose.

Where is Miss Wang —She went to Hainan Island last week and will return______ six days.

It’s really a great pity that all of you ____ leave so soon. It’s been pretty nice having you all at my birthday party.