Beethoven wrote _______ beautiful pieces of music.
I can't connect my computer to the Interrnet. There must be ______ wrong with it.
Mr. Li asks the students ______ in the river, because it’s too dangerous.
interesting subjects they are !
To live a green life, we should try to save ____ energy and produce__pollution.
-- Here is a schoolbag. Whose is it? -- Oh, it's ________. Thank you.