Electrical charges can be either positive or negative. Which of the following is true about electrically charged objects? A.
Positively charged objects cannot touch negatively charged objects.
B.
Positively charged objects will attract other positively charged objects.
C.
Positively charged objects will repel negatively charged objects.
D.
Positively charged objects will repel other positively charged objects.

Ascientist is investigating the effects of salinity on fish development. he places fertilized fish eggs in an aquarium that contains low salinity and observes their development. what factor would improve experimental design the most? place the fish eggs in the open ocean because that is the natural habitat include another aquarium that has normal salinity to compare to the low salinity aquarium include an aquarium that replaces salt with sugar to confirm that the effects are specific to salt grow algae with the fish eggs in order to provide adequate nutrients to the developing embryos