Answer:
W- developed seeds
X-angiosperm
Explanation:
Well for one, these two are the only things w/ a referrable image (I'm not sure if that's a word :-)) Another thing is angiosperm literally means flowering plant and a tomato is a ripe, or flowering, plant. W is an image of seeds that are at mid stage in there developing process, so it is clearly the answer. Correct me if im wrong :-D.
 
        
             
        
        
        
The structure is calcium ions.
        
             
        
        
        
Answer:
A control variable is the variable in the experiment that does not change.
Explanation:
If you are testing how seeds grow in different types of water, and you add 1tbps of salt to one pot of water with the plant, and then added 2tbps to another pot of water with the plant. The control variable in this experiment would be the water with no salt because it was not altered. 
FYI I did not pull from google. Good luck!
 
        
             
        
        
        
Answer:
 theme refers to the main idea or moral of the story. Sometimes this main idea or moral is stated directly, and sometimes the reader has to think about the main idea.
Explanation:
 
        
             
        
        
        
The answer for the year of 2017 would be more than 90 million. Hope this helps.