问题
选择题
. I wrote to my parents once a week,____ I was too busy with my teaching work.
A.it
B.unless
C.when
D.as
答案
.B
unless=if...not。
. I wrote to my parents once a week,____ I was too busy with my teaching work.
A.it
B.unless
C.when
D.as
.B
unless=if...not。