Simplify the following text for a Grade 10 native English-speaking person.
Original: Because children attend school longer now and have become much more familiar with the testing of school-related material , one might expect the greatest gains to occur on such school content-related tests as vocabulary , arithmetic or general information .
Simplified: They have also become more familiar with testing . It might therefore be expected that the biggest gains occur with school-related content , such as vocabulary , arithmetic or general information .