Nigeria is experiencing widespread water pollution in the niger river delta region. what is the primary cause of this problem? a. oil spills b. improper dumping by factories c. too many older vehicles on the roads d. too few laws to make polluting illegal

An education expert is researching teaching methods and wishes to interview teachers from a particular school district. she randomly selects ten schools from the district and interviews all of the teachers at the selected schools. which type of sample did she use in this study? a)systematic sample b)probability sample c)stratified sample d)cluster sample

Which of the following contributed most to making the items listed in the box

About how many crusaders took part in the crusaders