There're a lot of apples ____ the tree.a.on b.in

There're a lot of apples ____ the tree.a.on b.in
There're a lot of apples ____ the tree.
a.on b.in

There're a lot of apples ____ the tree.a.on b.in
on 绝对是,属于数的用on,不属于用in
比如birds in the tree