It was _____ great shock to the world that two airplanes crashed into _____ World Trade Centre in New York on Sept.11.
--- What do you suppose made her worried? --- _________ a new cell phone.
One third of our school _________ covered by trees, while the majority of our students ________ girls.
People in China don’t like hugging each other when meeting, which _________ a common __________ in some European countries.
___________, the northerners are fond of dumplings while the southerners are fond of rice.
Not ______ openly may make one’s point confusing, while careless words are ______ to hurt others’ feelings.