form the moon, our earth with water .seventy percent of its surface, appears as a blue ball.
30._______ I know about this competition is that it is held every two years.
29.Was it in the beautiful park _____was located by the sea ____we first met our new Chinese teacher?
28.Finding her car stolen,__________.
27.After the bell rings, which indicates the ending of the exam, you ______stay where you are until all your papers are collected.
26.With the college entrance examination ______near, both the parents and the students are more and more anxious.