So far, about 40 houses have fallen down under the weight of the snow, with 22 people _____.

下列各句中，表达得体的一句是

oday, poverty is still a big problemin the United States, ______ more than 10 percent of the whole population.

na, the number of cities is increasing ________development is recognizedacross the world

Just like fingerprints, each person’s DNA is ________unless he has a twin．