To enjoy the scenery, Irene would rather spend long hours on the train_____ travel by air.

________is known to us all that the old scientist, for ____________life was hard in the past, still works hard in his eighties.[ ]

__ I’m terribly sorry th__ ________.

You can encourage your kid to take part in those activities so that he can ______ his confidence by helping others in trouble.

______rise in carbon dioxide is causing _______ steady increase in global warming.