1. trên cây nhị phân ,nút cấp 2 là nút như thế nào trong các phương án sau đây?

the correct answer is a) her connection with a character

this is correct on edgnuity : )

answer///quick access toolbar;

only #2 represents an object at rest on a table.

in #1, there is no normal force due to the table; the object is accelerating downward.

in #3, the vertical forces are not balanced; the object is accelerating downward.

in #4, neither the vertical nor the horizontal forces are balanced. the object is accelerating upwards and to the right.