A number of students ______ playing on the ground but I don't know what the exact number______.
of the surface of the earth covered with water.
Johnson was the first on the list of the famous stars because he was the richest ___ them.
______ exciting news it is! Our government is doing something to stop the haze(雾霾).
-- Let’s see the pandas first. -- __________.
Either you or he ________ a shower first.