Tammy:Someoneisatthedoctor.

Richard:______.

Let's go swimming,_______?

Theday____(在那天我第一次遇见他)wasthefirstofMayontheGreatWall.

Thereason____(为什么这事情会这样)isnowclear.Idon'tneedtoexplainitoncemore.

The time has come _____ we make extensive use of nuclear energy.