sentences: sugar is a kind of solid & salt is a kind of solid ->  sugar and salt are solids  sugar and salt are solids & if solids are combined physically , then the physical properties of the solids will stay the same ->  if sugar and salt are combined physically, then the physical properties of the sugar and salt will stay the same  if sugar and salt are combined physically, then the physical properties of the sugar and salt will stay the same & a student mixed sugar and salt -> the physical properties of sugar and salt will stay the same