Answer questions about the disease bilharzia
25 points and brainliest

· what are the countries doing to solve the problem?

· what are the hindrances to solving the problem?

They are developing human and bovine vacines to target the life cycle of the parasite that causes it.Explanation:The disease is parasitic ,so they are starting from the source.

The chemicals used to eliminate the snails that are carriers may harm other species of animals,and if treatment is not on going the snail will just return.

the median of the data is 4.

step-by-step explanation:

the median means the middle number of a given number.

to decide which one is the median, arrange in ascending or descending order. but sometimes, you may find two(2) number in the middle, but it's easy, just add them together and divide by 2.

so,   determine the median of the data. 2, 3, 3, 4, 5, 7, 9

it is already arranged, count 3 times forward and 3 backward and the one left is your answer.

2,3,3,4,5,7,9

our answer is 4.

hope this !