Reword the following sntences, using the present perfect tense.(用 现在完成时 改写下列句子,注意主谓一致) Example lt two months since he earned any money. ---He hasn't earned any money for two months. It's three weeks since I last had a good night's sleep. Tips :since后面的句子提前,时态由一般过去式变为现在完成时;去掉since由介词for来接时间段;注意句子意思是表肯定还是否定。