Answer;
both positive and negative
Explanation;
-The elephant are keystone species, playing an important role in maintaining the biodiversity of the ecosystems in which they live. They may have both negative and positive interactions to the environment. For example, during the dry season, elephants use their tusks to dig for water, which has a positive impact to the surrounding. 
-They clear large amounts of vegetation, which removes habitats for some organisms but makes the area inviting for other organisms. This has both positive and negative impact to the ecosystem. 
 
        
                    
             
        
        
        
The waves do not help scientist
        
             
        
        
        
Answer:
At the end of 6 hours, 6 feet of the ladder remained above water
Explanation:
we are given the following:
change in tide = 8 inches per hour
1 hour = 8 inches 
∴ 6 hours = 8 × 6 = 48 inches
Now, since the length of the ladder is measured in foot, let us convert the rate of tide rising to foot.
12 inches = 1 foot
dividing both sides by 12:

Therefore, after 6 hours, the tide rises by 2 feet.
Next, we are told that the rope ladder at the beginning was 8 feet, hence the length remaining above water after 6 hours of the rising of the tide is calculated as follows:
 = 8 feet above water
height of tide = 2 feet = amount submerged in water
∴ length above water = (ladder before rising of the tide) - (amount submerged in water)
length above water = 8 - 2 = 6 feet
Therefore at the end of 6 hours, 6 feet of the ladder remained above water
 
        
             
        
        
        
Answer: The plant structures are correctly paired with its functions
Explanation: Dermal tissue: protected soft tissues of plants and controls interactions with plant surroundings(It covers the outer surface of herbaceous plants)
Parenchyma tissue: functions in storage, photosynthesis and bulk of ground and vascular tissue