@ pratiksha 
as u are in grade 7 , so, just cheer up , dnt take so much of tension as u have a future ahead . 
frst of all you have to mainly focus on ncert as its your main textbook . 
ncert u have to study twice , and while studying just take  apencil and underline the imp keywords written in black bold letter . 
after that for some difficult concept like planet system , etc u need to refer s.chand ref books , its also colourfull and intresting to study . 
and also u can avail study material from askiitians . 
HOPE IT CLEARS 
ALL THE BEST ..
						

							
you don’t bouther about it.you didn’study for marks,study only for knowledge.read it understand it and present it in your own way.
ALL THE BEST.
						

							
@ prati
you dont fear about the exams;you try to understand the subject ,you are know studing 7.you dont feel about marks try to understand the subject.
						

							The main thing is that you need to create interest in the subject. And this totally depends on how you create it. Secondly try to understand things rather than mugging them up.