Who among the following educators did not contribute to the study of play? a. jean-jacques rousseau b. johann amos comenius c. howard gardner d. friedrich froebel

i believe the answer would be 'd'.

hope this !

exposure to hazardous carcinogens and toxic substances can cause breathing problems, such as copd and various types of cancer. it also increases the risk of heart attacks and strokes and has serious (but no less unattractive) side effects, such as aging, yellow teeth, a terrible smell and damage to the vocal cords.