LAST YEAR WE INSTALLED ORDINARY LIGHT BULBS IN OUR HOUSE. NOW WE AR...

4. - KIEM TRA ANH 9- TIET PPCT: 47
KIEM TRA ANH 9- TIET PPCT: 47

4. Last year we installed ordinary light bulbs in our house. Now we are using energy-

saving ones. ( but)

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