What are DNA machines, according to Kraves?

they are machines or devices build to find la DNA trace and copy it multiple times.

Explanation:

DNA machines are machines built to find a DNA line and copy it multiple times, so scientists can read, observe, and find information about the DNA strand. For example, DNA machines can determine if someone is related, if someone has cancer, and it can distinguish a person’s ancestry. Mainly this is how forensic science uses to determine when there's a suspect in a crime.

Machines that can find any specific line of genetic information. They then copy the target gene until we are able to visualize it

Explanation: I watched the actual video

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.