Certain antibiotics are no longer effective against the bacteria that they used to kill. Which of the following best explains why certain antibiotics are no longer effective? The number of bacteria is now greater than what the antibiotic can kill

The antibiotic has become weaker over time

Bacteria that were resistant to the antibiotic survived to reproduce

Changes in the environment made the antibiotic ineffective

Identify the correct relation showing that the radius r of the orbit of a moon of a given planet can be determined from the radius r of the planet, the acceleration of gravity at the surface of the planet, and the time τ required by the moon to complete one full revolution about the planet. determine the acceleration of gravity at the surface of the planet jupiter knowing that r = 71 492 km and that t= 3.551 days and r= 670.9 × 10^3 km for its moon europa.