b
I am not that sure but I think endocrine cell don't contain blood vessels 
 
        
                    
             
        
        
        
Sternal angle marks the joint between the sternum and the 2nd rib. 
Option E. 
<h3><u>Explanation:</u></h3>
Sternum is the breast bone which is a dorsi ventrally flattened bone present in thorax of human. It gives the support for the ribs where the ribs join. A sternum has three parts - Manubrium sterni, body of sternum and the xyphoid process. 
The sternum has attachments of a total of 10 ribs and clavicle. The clavicle and the first rib joins in the Manubrium sterni, and the 3rd to 10th rib joins in the body of sternum. The 2nd rib joins in a facet which is partly in Manubrium sterni and partly in body of sternum. This place id also called the sternal angle. So the sternal angle marks the joint of 2nd rib to sternum. 
 
        
             
        
        
        
Answer: 
The correct answer is option b, 0.3m/s
Step by Step solution:
The relation between speed, wavelength and frequency of a wave is given by the following equation:  
Speed = Wavelength x Frequency
Substituting the values in above equation we get –  
= 3  x 0.1  
= 0.3 m/s  
 
        
                    
             
        
        
        
Answer:
C. They lose their gills
Explanation:
They lose their gills but grow lungs
 
        
             
        
        
        
Answer:
d
Explanation:
four daughter cells are produced in meiosis