题目

根据句意，写出括号内所给单词的适当形式。1.After reading the touching story, I know I should spend my money __________ (wise).2.The result of the writing competition is still under __________ (discuss).3. A Chinese __________ (medicine) team was sent to Nepal soon after the terrible earthquake     happened.4. All the children are often __________ (warn) not to swim alone in the river.如图所示的电路中，当S1闭合，S2、S3断开时，电压表的示数为6 V，当S1、S3断开，S2闭合时，电压表两极对调后示数为3 V。求：（1）电源电压是多少? （2）当S1、S3闭合，S2断开时，电压表的示数为多少?