题目

As is estimated, more than 20 million shared bikes ______ into operation nationwide by 2025.A.will have been put B.will have put C.have been put D.will be putting 答案：【答案】A【解析】考查动词时态语态。句意：据估计，到2025年为止，全国将有2000多万辆共享单车投入运营。根据by 2025可知应用将来完成时，且主语与谓语动词构成被动关系，故应为将来完成时的被动语态。故选A。若直线x-y+1=0与圆（x-a）2+y2=2有公共点，则实数a取值范围是 ．