Which of the following statements is true?

When did stem cell research become known ? who discovered stem cell? what experiments or studies have been conducted so far?

One student said that the investigation was not valid (a fair test). write a plan for the investigation that includes improvements to the method and apparatus

What makes up a film badge? layers of photographic film covered in black paper. an electrolyte paste spread across a plastic sheet. a thin film of salts and other chemicals on clear acetate. a panel of photographic film exposed to the air. ✓