题目

At one time, about 300 native languages were spoken on the Australian continent. Only about 90 of them are still spoken today.European settlers arrived in Australia in the late 1700s. Experts say that colonization had a harmful effect on native languages. Now, only about 60 of them are considered “alive” and in daily use. As older members of tribes die, other languages are likely to pass away.In the central Australian desert, only 20 people are fluent in Pertame, a language native to the area. But now, children are being taught its ancient words in hope that it won't die out.Bradshaw and S两个开关S1和S2控制一盏灯．要求：闭合任意一个开关，灯就能发光，只有当开关全部断开时，灯才熄灭．根据要求画出电路图．