According to Darwin's Survival of the Fittest, only those species that were able to ______ the sudden great changes of their living conditions survived.
—Shall we go out for meal this evening? —Yes,that’s good idea.
I don't know if you noticed their behaviors or not, but we______.
Here is the tower, ______ top you can have a good view of the whole city.
This house is that one.
—Well.Randy is not quite ready to make a decision yet.—So,,we have to wait,right?