The genetic engineering, ______ progress has been very rapid recently, is perhaps the most important of all the sciences．

I don’t believe that he will marry Kathy whom he doesn’t love at all,________?

The taxi was so slow that we might as well _________ on the bus

Daddy, I don’t want to go to Jimmy’s birthday— You had better go____ you make a promise, you have to keep it

You have a beautiful voice. I love your songs. —____________