资料：Did your child"s brain shrink last summer? Probably not, but it may have shifted into reverse, according to a study by Dr. Harris Cooper, professor of psychology at the University of Missouri-Columbia. The study found that when students return to school after a long summer vacation, they"ve lost one to three months worth of learning. The decline is more detrimental for math than it is for reading. "All students lose math skills," says Cooper. It may be because community and home environments give kids more opportunities to practice reading than math. The study also found that income has an impact on how much a student loses or gains in reading. Middle-class children actually gained in reading over the summer, while lower-income students experienced losses. Cooper attributes this to the enrichment activities that many middle-class kids participate in over the summer, such as camp and trips. Your kids don"t have to spend the summer stuck in reverse. "Parents can help their kids retain educational skills," says Cooper. He suggests the following five tips to kick off a learning-filled summer. 1. Keep lots of books around and make regular trips to the library. Most libraries schedule special summer events for kids. Sign up your family! 2. Think about what your kids may be learning next year when you plan the family vacation. Talk with teachers to find out what they"ll be covering in class. If it"s a unit on the civil war for example, you may want to schedule a visit to Gettysburg. If it"s geology, visit a national park. 3. Keep math in mind. Since kids lose more math skills than anything else over the summer, try to do some special planning to find math-related activities. For example, if you can"t decide whether to sign your child up for "Shakespeare"s Theater" or "Math Magic" at the local community center, go with the math. 4. Consider summer school or tutoring. Struggling kids can get a lot of different kinds of help from these programs. Summer school can also enrich and accelerate learning in areas where kids show a special interest. 5. Call the curriculum coordinator in your child"s school district, visit the school board office, or contact the schools of education at local colleges and universities to find out what educational programs will be offered in your area over the summer. Remember to keep it fun! You don"t want to sour your kids on learning during the summer break. What dose Dr. Harris Cooper’s research find？（ ）