He wrote a letter ______ he explained what had happened in the accident. 
#75781
A
what
B
which
C
where
D
how
推荐题目
The river ____are covered with trees is very long
#76405
A
which banks    
B
of which banks
C
whose the banks  
D
the banks of which
They are walking down the way _______ there are many trees on ______side.
#76307
A
that, both
B
in which, either
C
on which, either
D
/, neither