There are recycling of books. For example, at PEA, at the end of each term, students can take their textbooks back to the bookstore to sell back to the school. Students can also buy used books if they don’t want to spend a lot of money on new books. I personally would recommend buying used books since there might be useful information written into the book.
Normally each class would have one textbook. Sometimes the subject teacher may not require you to bring the textbook to class. There are also classes that have open book exams. So it all depends on the teacher and the subject.

In the US, kids do not use pulling luggage. Most kids would use backpacks. So if you don’t want to look different than other students, suggest you use a backpack that has good support for the back.

也要看学校。有的私立学校课本也要收回的，供下一年的学生使用。一般，学校会在给家长的信中提及是否要自己买书，或者是用学校的书。

美国高中数学物理教师

课本要自己买。可以买旧书。用过的课本也可卖给下一级的同学。

私立学校自己买的课本,当然不回收. 公立回收是因为课本是免费使用的.
美国的教科书死沉死沉的,再加上大的binder,反正能把孩子的肩膀给压垮了.现在不少都用电子版本,这样能减轻一些负荷.
书包买Jansport这个牌子好了,用一到两年没有问题.