Up to Tuesday's attack, the worst school shooting in the U. S. was in March 1998 in Jonesboro,________ two boys, aged 11 and 13, shot and killed a teacher and four girls.
We must do whatever we can to ______the river from being polluted any more.
We should try our best to___________ those people after the disaster.
— I’d like to take a week holiday. — ________, we are too busy.
---Are you going to attend the meeting _____ next Saturday? ---I won’t unless invited.
________ excited Geoff Marcy most was ________ there were planets in other solar system where life might exist.