In summer, food goes sour easily ________ it isn’t put in the fridge.
Computers of this kind __________. They are out of stock (脱销) now.
My teacher has given me lots of __________. They’re very useful.
—Do you like tea or coffee? —Coffee. I prefer coffee __________ milk.
What __________ good time we had having a picnic yesterday!
We never know____________ because happiness is everywhere.