Which protein serves as a chemical messenger

Many state and local authorities are making laws regarding recreation on lakes, rivers, and oceans to reduce water pollution. why would lawmakers need to consult with scientists before making these laws? a) to make scientists feel important b) so that the laws reduce pollution by a sufficient amount c) so that parks and lakefront facilities will still make large profits d) so that the public will believe that the laws are important to follow

Secondary succession would most likely be taking place in a(n)

Suggest why placing wheels under a heavy box reduces the neccessary force required to push it along at a constant speed.