—How long do you think it is ________ he arrived here? —No more than half a year, I believe.
. The _______ boy was last seen _______ near the East Lake.
Don’t leave the water_______ while you brush your teeth.
The salesman scolded the girl caught ______ and let her off.
11. Though I have often heard this song ______, I have never heard you ______ it.
____________, they have been struggling against the snowstorm for ten hours.