Nine-year-old Sochi is studying weather differences in the United States. She learns that it rains more in Hawaii than it does in Washington and more in Washington than it does in Oregon. Therefore, she concludes that it rains more in Hawaii than it does in Washington and Oregon.
Which concrete-operational principle is Sochi demonstrating?

a) Transitivity
b) Reversibility
c) Conservation
d) Seriation

a) Transitivity                                      

Explanation:

Transitivity: In psychology, the term "transitivity" is described as one of the principles associated with the concrete-operational stage which is considered as one of the different stages of the cognitive development theory and was given by a famous psychologist named Jean Piaget.

Transitivity is considered as an important aspect of the concrete-operational stage and is referred to as an individual's capability to recognize relationships between different things in a "serial order".

In the question above, the given statement represents that Sochi is demonstrating transitivity.

your answer is "graduates" hope this

question - in 1827, john walker, a druggist in a small english town, tipped a splint with sulphur, chlorate of potash, and sulphid of antimony, and rubbed it on sandpaper, and it burst into flame. the druggist had discovered the first friction-chemical match, the kind we use to-day. it is called friction-chemical because it is made by mixing certain chemicals together and rubbing them. although walker's match did not require the bottle of acid, nevertheless it was not a good one. it could be lighted only by hard rubbing, and it sputtered and threw fire in all directions. in a few years, however, phosphorus was substituted on the tip for antimony, and the change worked wonders. the match could now be lighted with very little rubbing, and it was no longer necessary to have sandpaper upon which to rub it. it would ignite when rubbed on any dry surface, and there was no longer any sputtering. this was the phosphorus match, the match with which we are so familiar. according the paragraph what was the benefit of the new phosphorus match? it burst into flame when rubbed on sandpaper. it was made by mixing chemicals. it could be ignited on any dry surface. it threw fire in all directions.

answer - matches required natural chemicals