A certain large pond had many plants growing in it. It also had a population of fish living in it. One day, a chemical spilled into the water. This chemical caused the plants to die. A scientist monitored the pond after the chemical spill. She found that the amount of dissolved oxygen in the pond gradually decreased. Once it reached about half of its original amount, the fish in the pond began to die.

Which statement best explains this information?

A. Fish produce oxygen through respiration, and this oxygen is used by plants.

B. All the oxygen in a pond comes directly from the atmosphere, so fish do not need plants.

C. Plants produce oxygen through photosynthesis, and fish depend on this oxygen to survive.

D. Fish and plants compete with each other for the dissolved oxygen in a pond.

Pls help!!

the answer is the first option

explanation:

just googled it m8. not that hard

lol

chemical digestion occurs in the stomach were hcl and pepsin forms chyme, the mouth in which salivary amylase breaks down starch to form bolus, and the small intestine specifically the duodenum.

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.