Answer:
The frogs circulatory and digestive systems are physically connected because the frog’s digestive system includes its liver and this has a hepatic portal system through which veins pass and come out and that is the circulatory system so they are connected.
The answer is the first option.
"They perform well only at very low temperatures."
Despite of advantages of Superconductors such as power and cost efficiency, these conductors have drawbacks. Semiconductors have restricted operation range of operating temperatures. They are required to work at very low temperatures.
To make changes to it or to take out some genes of interest
