If you need to translate, the answer is
Chemical agents concept
The contraction of the triceps muscle causes the arm to flex. The contraction of the triceps muscle causes the arm to extend. When added to the force of the biceps contracting it provides extra force to the ball.
The answer is A
B, because water is changing its state from solid to liquid (it's fusion in portuguese, don't know in english), so while it's changing, water has 2 states at the same time.
There are three elements hydrogen, chlorine, and oxygen
