examining the structure of plant cells
Answer:

Explanation:
Given :
Mass of a bar of lead = 115.2 g
Initial water level
= 25 mL
Final water level
= 35.5 mL
Difference in the water level = 35.5 - 25
= 10.5 mL
= 
We know that when a body is submerged in water, it displaces its own volume of water.
Therefore, the volume of the lead bar = volume of the water displaced = 10.5 mL = 
We know that mathematically, density is the ratio of mass of body to its volume.
Density of the lead bar is given by :


= 
Answer:
b Fuel for fusion reactors can be extracted from ocean water.
Explanation:
The fuel is deuterium, which makes up 0.02% of the hydrogen atoms in water. The oceans contain more than a billion cubic kilometres of water, so that's a lot of deuterium.
a is wrong. The fuel for fusion reactors is deuterium.
c is wrong. There is much research, but there are no large-scale fusion reactors in operation.
d is wrong. Fusion reactors do not produce radioactive waste as spent fuel. Most of the radioactive waste would be the reactor core itself.
Because it tilts on its axis