Question

instructions: read the passage(s) below and answer the question based on what is stated or implied in the passage(s) and in any introductory material that may be provided. passage: every day is a curly - hair day for sheep. those curls are part of what makes woolen sweaters so cozy - the mass of fibers helps trap warm air, keeping it close to the body. but wrapped up in those curls may also be answers to a long - standing mystery: exactly how a strand of hair winds itself into a curl on the cellular level. for many years, there were two competing theories to explain what makes hair curl in sheep. research by scientists in new zealand and japan published in the journal of experimental biology finds that neither theory is exactly correct. but it remains likely that differences between certain cells on a hair may explain what makes a sheeps wool curly. and while human hair has some crucial differences from wool, understanding why curls happen in one mammals hair could eventually shed light on others, including ours. adapted from henrique greenwood, \what makes some hair curly? not quite what scientists thought.\ ©2018 by the new york times company. question: in context, the main purpose of the second paragraph is to disprove a long - held theory that differences between certain cells are what cause sheeps wool to curl describe the research methodology used by scientists to study why sheeps wool is curly illustrate why certain cellular differences among mammal species make it hard to definitively explain the cause of curly hair introduce a research study that has furthered scientists understanding of why hair curls

Explanation:

The second - paragraph mentions research by scientists in New Zealand and Japan which finds neither of the two competing theories about what makes sheep's wool curly is exactly correct, and that differences between certain cells on a hair may explain it. This research has furthered scientists' understanding of why hair curls. It doesn't disprove the cell - difference theory but rather refines it, doesn't describe research methodology in detail, and isn't mainly about how differences among mammal species make it hard to explain curly hair.

Answer:

Introduce a research study that has furthered scientists' understanding of why hair curls