题目

某种病毒似于球体，它的半径约为0.00 000 000 495，作科学记数法表示为                 . 答案：4.95*10—When will the engineer go to Singapore?—Oh，I don’t know when he ___Singapore．When he ____ Singapore，I will call you．A．leaves for；leaves forB．will leave for；will leave forC．will leave for；leaves forD．leaves for；will leave for