This probably won't help since this was a year ago but here it is:
The diaphragm adjusts the amount of light on a light microscope.
 
        
             
        
        
        
Answer:
The given blank can be filled with cohort effect. 
Explanation:
A cohort effect refers to the specific influence of a group bonded by common life experiences or time. Cohorts in an organization are generally illustrated by entry date and retain some common features like cohesiveness, size, and competition, which can influence the organization.  
A cohort refers to a group of individuals who shares common experiences or features like the region where they were born, their years of birth, and others. Cohort effects are a concern for the scientists working in the fields like epidemiology, sociology, and psychology.  
 
        
             
        
        
        
Answer:
Step 1. 1:100
Step 2. 1:1000
Step 3. 1:100,000
Explanation:
At first step, 0.1 ml is diluted in 9.9 ml of saline. Multiple both with 10 you will get 1 ml in 99 ml suggesting total dilution at first step as 1:100.
At second step, 1 ml of 100x dilution will be taken and further dissolved in the 9 ml of B3. Here, the dilution factor is further 10 times therefore the total dilution would be 1:1000.
At third step, 0.01 ml would be taken from 1000x dilution and further diluted in 9.99 ml. Therefore, the dilution factor here is 100 times. Hence the final dilution at this stage would be 1:100,000.
This is the simplest explanation I can give. 
Hope it helps.
 
        
             
        
        
        
Answer:
The correct answer is star,moon,planets,moons, astroid and comets galaxy universes planets,moon, comets and astroids.
Explanation:
The above answer is correct
 
        
             
        
        
        
Both chordates and invertebrates have pharyngeal pouches