Hans Lippershey, also known as Johann Lippershey or Lipperhey, was a German-Dutch spectacle-maker. He is commonly associated with the invention of the telescope, although it is unclear if he was the first to build one.
Answer: Differential Selection
Explanation: Differential Selection this is a selection threat with greatest concern when subjects cannot be randomly assigned to a treatment group, particularly if the groups had being unequal when the relevant variables were being considered before treatment intervention. By giving each participant pencils and stickers she is decreasing the threat of differential selection.
The system of checks and balances in the US Federal system protects Democracy as it keeps the Executive or Legislative branches from acting unconstitutionally and not abiding by the Democratic process.
The <span>Philippines
hope this helped! plz mark brainlest for me plz tysm </span>
