I don’t think it easy, even if we work hard,           the South Korea and the North Korea to sit down to talk at present.

Not easy as the problem of pollution is____, no one should just stop trying.

One Sunday several former classmates gathered at Tom’s for lunch, ______ their high schoolreunion the year before.

_______the room，I found my cat lying on the floor，dying．

Allen followed his customer across the yard and stood on the step of the house,        two shopping bags.