【2014呼和浩特】If we ______ take environmental problems seriously, the earth _______ worse and worse.
― How do you feel when you watch the national flag go up? ― It makes me ________ very proud.
— Which month has ________ days in a year? — February.
We should never ________till tomorrow what we can do today.
Bob ________to Harbin for a meeting yesterday.
I still remember my first teacher________ we haven’t seen each other for a long time.