It is these poisonous products _____ can cause the symptoms of the flu, such as headaches and aching muscles.
—Did you enjoy your holiday? —Yes, it’s the best holiday Ithese years.
Just look at the room. My roommate ____ up his clothes.
I ____ to send him a telegram to congratulate him on his marriage, but I ____ it.
—It’s a long time since we met last. Haven’t you graduated from college yet? —_____. I ______ English for four years in Nanjing University.
Unluckily, when I dropped in , Dr. Smith ____, so we only had time for a few words.