根据下面资料，回答题
According to statistics, in 2007 more than 6,000 children were expulsed (开除) from US schools for bringing guns and bombs to school.
The US Department of Education gave a report to the expulsions as saying handguns accounted for 58 percent of the 6,093 expulsions in 2003-2004, against 7 percent for rifles(步枪) or shotguns and 35 percent for other types of firearms. "The report is a clear sign that our nation´ s public schools are cracking down (严惩) on students who bring guns to school," Education Secretary Richard Riley said in a statement. "We need to be strong-minded about keeping guns out of our schools and do everything to keep our children safe. " In March 2004, an 11 years old boy and 13 years old boy using handguns and rifles shot dead four children and a teacher at a school in Jones-boro, Arkansas. In October, two were killed and seven were wounded in a shooting at a Mississip-pi school. Two months later, a 14 years old boy killed three high school students and wounded five in Dasucah, Kentucky. Most of the expulsions,56 percent, were from high schools, which have students from about age 13.34 percent were from junior high schools and 9 percent were from ele-mentary schools, the report said.
From the first paragraph we can infer that in the US schools__________．