Answer:
The correct answer is 
18
Groups of the periodic table: The s-, p-, and d-block elements of the periodic table are arranged into 18 numbered columns, or groups.
Hope this helps! 
- Quinn <3
 
        
             
        
        
        
They survive without water by entering a special mode, otherwise called as shriveling. They can lose even 95% of water in their body and still live, even though they would look like dead plants, they would actually be alive. In the absence of water, tardigrades use a sugar called trehalose, which becomes their source of life until they find some water.
        
             
        
        
        
I think it is stage 2
At stage two, the skin breaks open, wears away, or forms an ulcer, which is usually tender and painful. The sore expands into deeper layers of the skin. It may appear as a scrape, blister, or a shallow crater in the skin. At times this stage looks like a blister filled with clear liquid. Also at this stage some skin may be damaged beyond repair or may die.
        
             
        
        
        
The answer is B. Scientist repeat the experiments in order to prevent bias. 
Brainlest answer is always appreciated!
        
             
        
        
        
Answer:
pacemaker cells.
Explanation:
Cardiac muscle tissue works to keep your heart pumping through involuntary movements. This is one feature that differentiates it from skeletal muscle tissue, which you can control. It does this through specialized cells called pacemaker cells.