Sperm penetration tests check to see whether a man's sperm can move through cervical mucus and the fallopian tubes to join with (fertilize) an egg. This test is usually done when a couple is having trouble becoming pregnant (infertility). There are different sperm penetration tests.
The idea that a boundary is shifting can be applied to different areas. A shifting frontier of science would be referring to the fact that science is always changing and growing, and always with new areas. In wartime, a shifting frontier would be an international border which is constantly being renegotiated.
A cultural boundary refers to the presence of some kind of cultural differencecultural boundaries are characteristic of all human societies, traditional as well as modern. A border is a social construct that is political in origin.Across a border power is exercised, as in the political border between two nations. cultural boundary refers to the presence of some kind of cultural differencecultural boundaries are characteristic of all human societies, traditional as well as modern. A border is a social construct that is political in origin. Across a border power is exercised, as in the political border between two nations.