Give one reason why the antibody level drops after reaching the immunity level

Which of the following pairs of elements belong to the same groupa. h and he b. li and bec. c and pb d. ga and ge

Which are examples of how technology has advanced scientific understanding.1using hot water to sterilize medical equipment.2transplanting a human organ into another individual.3inserting genes from one sheep into another cell to make a cloneunderstanding the different structures that make up a cell.4examining microorganisms from the deepest parts of the ocean

What is the value of the standard enthalpy of formation of an element in its most stable form?