In order to contain groundwater, a layer of subsoil must have porosity. that is, it must have empty spaces, or pores. in order to allow groundwater to easily pass through the subsoil, a. the subsoil's pores must be large. b. the subsoil's pores must be connected to each other. c. the subsoil's pores must be small. d. the subsoil's pores must be isolated from each other.

Several bird species feed in a certain species of tree. each bird species feeds in a different part of the tree. which statement is true of these bird species? a. they have adapted to different niches due to competition b. they have a carnivorous relationship with the tree species. c. they have adapted to different niches due to predation d. they have a symbiotic relationship with the tree species.

Which box will not accelerate? 4 newtons 4 newtons 4 newtons 25 kg 4 newtons 15 newtons 10 kg 30 newtons 40 newtons 50 kg 30 newtons 30 newtons

Which of the following is a limitation of a clinical trial? a.)amount of random assignments b.)hospital cost c.)number of test tubes d.)amount of peer review