【题文】 Children under age 6 should try their best not to use cellphones or computers, the National Health Commission has said, in a bid to protect them from nearsightedness. The commission also advised against parents using electronics before their children. The advice came when the commission recently made public the results of a survey on nearsightedness among children and youths. The survey found that 53. 6% of Chinese children and teenagers had suffered from nearsightedness in 2018. The nearsightedness rate was 14. 5% for 6-year-olds in kindergarten, 36% for primary school students, 71. 6% for junior middle school students, and 81% for senior high school students. The commission said age 0-6 is a serious time to develop the ability of seeing, and special importance should be put on the protection and health of eyesight at an early stage. It added that the most important cause of nearsightedness is that children spend too much time watching cellphones, computers and televisions. At primary and middle schools, teaching with electronics should be controlled to no more than 30% of overall teaching time. After classes, students should take a rest of 10 minutes after using electronic products for learning for 30-40 minutes. Children shouldn't spend more than one hour a day using electronic products for fun. In addition, the commission made suggestions on outdoor exercise. It said children and teenagers should control the continuous use of eyes in reading and writing to no more than 40 minutes and leave enough time for outdoor activities in the daytime. Teachers and parents should guide children to actively take part in exercise, with around two hours of outdoor activities in the daytime. China made a plan last year to stop the rise in nearsightedness among children and teenagers. It wants to keep the nearsightedness rate among 6-year-olds at around 3% by 2030, and the rate among junior and senior high school students below 60% and 70%.【小题1】What does the underlined word "electronics" refer to? A．Cellphones and computers. B．Letters and cellphones C．Computers and magazines. D．newspapers and computers 【小题2】Students in________ have the highest percentage of nearsightedness. A．kindergarten B．primary school C．junior high school D．senior high school 【小题3】Which of the following is the most important cause of kids' nearsightedness? A．Kids spend too much time on their homework. B．Kids spend too little time doing eye exercises C．Kids spend much time on electronic products D．Kids spend too little time doing outdoor exercise 【小题4】The main idea of Paragraph 4 may be that________. A．it's very bad for kids to use electronic products B．children should use electronic products properly C．children should use electronic products in class D．it's difficult for kids to use electronic products