A perfect flower is a m<span>onoecious flower. This means that the perfect flower will have both male (stamen) and female (carpel) parts while an imperfect flower may be missing certain parts of either sex but they will not have both. </span>
The Correct answer is A.
As snow becomes compressed , air between the flakes gets trapped. The process involving trapping of air occurs during burial of snow layers and is generally not complete until the bubbles are about 60 meters or more below the surface.
Once the bubbles have formed, they act as the time capsules of the atmosphere when they were trapped. By extracting the air from the bubble in ice cores, changes in the past can be studied .
Studies of these changes show the dramatic increase of what are called greenhouse gases such as carbon dioxide, caused by human use of fossil fuels, as well as natural changes that accompany glacial climate
The third choice is the answer.
This is because chemical change occurs when the (for a lack of better wording) interior of the object is changed in the second one the bread is being broken down chemically by the stomach acid this is because the acid is breaking down the formation of the bread dissolving it and chainring it into something else.
In the 4th one the change that is seen is chemical because the formation of the roof is change the physical appearance may be the same (ie. The size & shape) but their are other changes in the color, texture and maybe taste ( don’t taste a rusting roof lol) these are ways in which you can figure out if a change is chemical or physical.
Physical change occurs when the size and/or shape of an object is changed.
Chemical change occurs when the texture, taste and/or color of the object is changed, but-sometimes chemical change cannot be seen.
Hope this helped :)
Answer:
bcuz in which habit they have been addicted they can't change it easely after a long try also so it is hard to get people to change their behavior