The big bang is thought to have occurred __billon years ago

With i really need the correct answer!

This is important. 1. which of the following is an si base unit for measuring length? (2 points) inch gram meter mole 2. which of the following units for distance is an si unit? (2 points) centimeter foot inch yard 3. which of the following tools should a scientist use to measure an object in meters? (2 points) electronic balance pan balance tape measure thermometer

Sort the images based on whether there's a force of attraction or repulsion between the magnets shown. attraction repulsion