(C) 40 km/s 
Explanation: 
Divide your km/s and your seconds. 
Equation: km/s divided by seconds = acceleration 
- 280 km/s divided by 7 seconds = 40 km/s acceleration 
Hope this helps you 
 
        
             
        
        
        
Answer:
4 km
Explanation:
There are 1.60934 km in a mile
2.5 m * 1.60934 km = 4 km
 
        
                    
             
        
        
        
Answer:
notochord, a dorsal hollow nerve cord and pharyngeal slits. 
 
        
             
        
        
        
If the sperm cell fertilises the ovum, and implantation does not occur, then the corpus luteum degenerates and it turns into corpus albicans, stopping progesterone secretion. If fertilisation occurs and implantation also, the syncytiotrophoblast, the "root part" of the blastocyst (one of the early structures originated from the zygote), produces a hormone that is called <span>human chorionic gonadotropin (hCG). The hCG is what makes the corpus luteum keep secreting progesterone and maintain itself. The progesterone will then help keep the endometrium and, therefore, allow the development of the embryo to happen.</span>
        
             
        
        
        
Answer:Mechanical digestion physically breaks down food, like when teeth macerate food into a bolus. The stomach contracts and relaxes in a churning motion. ... Chemical digestion occurs when the bonds within larger food molecules are broken, creating smaller molecules that the body can use.May 30, 2017
Explanation: