I'd say b, precise, here.
If there's an error somewhere in the experiment or project, then it is consistently .... wrong. So, just 'cos you measure something precisely, it doesn't mean that you've measured it accurately. Maybe an example would be a measurement of length. If you used a metal ruler at zero degrees C, you can measure to say half a millimetre. A series of measurements of the same object would give very similar readings. But, if you used same metal ruler at, say 100 celsius (implausible) then you'd probably get a different set of readings. 'cos of the expansion of the metal ruler.
Because we dont reproduce the way plants do
Answer:
1. E x 4πr² = ( Q x r³) / ( R³ x ε₀ )
Explanation:
According to the problem, Q is the charge on the non conducting sphere of radius R. Let ρ be the volume charge density of the non conducting sphere.
As shown in the figure, let r be the radius of the sphere inside the bigger non conducting sphere. Hence, the charge on the sphere of radius r is :
Q₁ = ∫ ρ dV
Here dV is the volume element of sphere of radius r.
Q₁ = ρ x 4π x ∫ r² dr
The limit of integration is from 0 to r as r is less than R.
Q₁ = (4π x ρ x r³ )/3
But volume charge density, ρ = 
So, 
Applying Gauss law of electrostatics ;
∫ E ds = Q₁/ε₀
Here E is electric field inside the sphere and ds is surface element of sphere of radius r.
Substitute the value of Q₁ in the above equation. Hence,
E x 4πr² = ( Q x r³) / ( R³ x ε₀ )
If you walk 3m in a straight line then turn 60 degrees until you are standing at your original position then you have walked a hexagon