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.
The cost of organic food is higher than _____ of conventional food because the organic price tag reflects more closely the true cost of growing the food.
The mobile phone has become a major means of communication, _____us to keep in touch as well as to surf the Internet to keep us _____of the latest news.