根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两多余选项。 There's an old saying, “You can put more salt in the soup，but once it's in there，you can't get it out.”__ 1 __ And your child can help！Here's an exciting experiment for your child to try： Start by helping your child to mix salt into the water in the mixing bowl and stirring until it is fully dissolved溶解）． ___ 2 __ Make sure that you don't let any of the salty water into it. ___ 3 __ Then take a small rock，and place it right on top of the center of the plastic wrap，so that all of the plastic leans slightly toward the middle of the bowl where the cup is. Put the whole setup in full，hot sun，and wait. Within an hour, you should see water droplets begin to form on the underside of the plastic. __ 4 ___ Wait, and then take the plastic off. A good amount of water should be in the small cup. __ 5 __ Guess what? No salt！The water vaporized蒸发）in the heat of the sun，and then returned to its liquid state. Salt doesn't do that一it stayed behind. You really can take the salt out of salt water！ As it happens，this is an excellent lesson in the way matter can change states. A．Fresh water is scarcer than ever. B．Invite your child to taste with you. C．Water can go from liquid to gas and to liquid again. D．Cover the bowl with plastic wrap and seal the edges. E．Then place a cup or a smaller bowl into the center of the bowl. F．They'll flow and drip into the center of the bowl，and into the cup. G.．Today, scientists are busy exploring ways to take the salt out of salt water in large quantities.