Lichens represented by this symbiotic relationship for primary succession
i just think
Answer:
Option D, 63 cm
Explanation:
The scale of model is of local park is 
This means that each dimension of the model is 21 times smaller than the actual park (to be developed in future)
Given -
Depth of the pond
centi meter
Depth of the real pond will be 21 times of the depth of the model.
Thus , real pond's depth is equal to
cm
Hence, option D is correct
The first step begins with: A. the mouth.
I am going with x-rays; it is the most visible to the naked eye out of all the choices.