题目

20世纪中期以来，在前两次工业革命的基础上，人类取得重大突破的技术领域有（） ①机械技术 ②电力技术 ③信息技术④空间技术 A . ①② B . ③④ C . ①④ D . ②④ 答案：B 阅读短文，根据所读内容在文后1～10的空格里填上适当的单词或短语。注意：每空不超过3个单词。 　　According to a new study, preschool boys perform better on tests that measure learning and other important skills when they are in classes that have more girls than boys．This doesn’t seem to apply to girls, though．For preschool girls, the presence or absence of boys does not affect learning． 　　“The study raises questions about having all-boy or all-girl classes for preschool”, says psychologist Arlen Moller, who led the study．She added,”Previous researches have shown that high-school girls may study better in all-girl schools．In middle school, however, the effects of same-sex schooling are unclear, and even less is known for very young kids．”To find out, researchers studied 70 preschool classes with a total of 806 children who were between 3.5 and 6 years old．For each class, teachers recorded the student’s progress over a 6.5-month school year． 　　Their data included scores of motor skills, social skills and thinking skills．Researchers found that boys developed each of these skills more quickly when there were more girls in the class than boys． 　　In majority-girl classrooms, boys developed at the same rate as girls．But in classes where boys were the majority, boys developed more slowly than girls．Girls tended to advance in classrooms which had any combination of boys and girls． 　　The study is one of the first to look at how the proportion of boys and girls in a class affects learning．Because it’s a new finding, researchers don’t know why this difference exists． 　　“This is an exciting topic, but it’s too early to draw any conclusion because this area is so under-explored,”says psychologist Lean Malofeeva of the High/Scope Educational Research Foundation in Ypsilanti, Michigan．