I think that about half of all babies are able to walk independently by 12 month of age. It said that babies tend to take their first steps from the age of 9. Babies usually start to crawl before they can walk. This is because their arm are usually more effective. After crawling they learn to stand up with their feet first and later learn to walk while holding things. The next step after that is walking. 
Not all babies walk at the same time. There those that learn before the other so there is no need to worry if your child does not walk by 12 months.
        
             
        
        
        
He or she is said to be in a positive
nitrogen balance state.
Nitrogen balance is the
traditional method of determining dietary protein requirements. Determining
dietary protein requirements using nitrogen balance requires that all nitrogen
inputs and losses are carefully collected, to ensure that all nitrogen exchange
is accounted for. Positive nitrogen balance is associated with periods of
growth, hypothyroidism, tissue repair, and pregnancy. This means that the
intake of nitrogen into the body is greater than the loss of nitrogen from the
body, so there is an increase in the total body pool of protein.
 
        
             
        
        
        
Answer:
Echinoderms evolved from animals with bilateral symmetry. Although adult echinoderms possess pentaradial, or five-sided, symmetry, echinoderm larvae are ciliated, free-swimming organisms that organize in bilateral symmetry which makes them look like embryonic chordates.
Hop you have a great day :)
Explanation: