The book was so interesting that he had read it for three hours ______ he realized it.( )
before
after
until
since
()—Yesterday I received a letter from John. —You did? I hear he _______ for America next year.
—I called you several times this afternoon. Why didn’t you answer the phone? --I’m sorry. I ________ an important meeting then.
Look! The police ______ the food onto the bank of the river.
– Alice, would you mind not playing the guitar? I ______ on the phone. – Oh, sorry, mom.
---Where is Peter? --- He ___________ dinner for his parents at home.