AAB
No particular undergraduate course of study is required for admission into law school. The important issues are that you have excellent grades and score well on the LSAT.
There are no prerequisite subjects for law. Excellent grades and a high LSAT score are essential.
No, you just need 3 a's at a level.
The most important thing is to get good grades to get into college. Once in college, good grades continue to be important to get into law school. The course of study is not critical, but most colleges have a pre-law curriculum that will provide a solid foundation for law school.
constitution
most of the skills you use for history you need them for law
I am not sure but I think between 90 and above and maby if you got 85 it is okay.
English you have to get an A in Science you have to get an A in
In order to become a child custody lawyer, first you have to be accepted into law school, and then graduate from law school. You will also be required to write the Bar Exams in your jurisdiction, following which you will be "called to the Bar." At that point, you will be a lawyer and you can (within reason) choose what type of law you will practise. The hardest part of becoming a lawyer is getting accepted into law school. High school grades are seldom reviewed in the law school admission process. Excellent grades in university are definitely required. Some say that philosophy courses are suggested for undergraduate study. Generally speaking, however, no particular field of undergraduate study is preferred over any other.
Depending on the subject, you will need equivelant AAB in A-Levels. If you have these results there is no guarentee that you will be accepted. You will have to attend two interviews, and competition for places is very fierce. Cambridge also appose grades obtained in re-sits, and expect you to achieve good grades first time round.
Good enough grades to get a BA or BS, pass the law school test to get into law school, go to law school, and then pass the bar exam. If you are the type of student who doesn't pay attention in class or turns in work late or not at all I would suggest you improve your study skills or think of another profession. The profession of law means that you need to have history, law, critical thinking skiils, writing skills, reading skills at an upper levels.
There really isn't much to "study" there - there is simply a law that states that mass can't be created or destroyed. As to the "why we need to study...", well, it's a fairly fundamental part of how our Universe works.