In my economics class, we are doing perfect competitive markets. I can't figure out which one is a long run or a short one. Could someone explain the difference to these questions?

Q: Determine whether the outcomes are in the short run or long run for a perfectly competitiv Firms have variable costs Choose... Firms have fixed costs Choose... Firms can earn a profit Choose... New firms can enter the market Choose.. Firms cannot eam a profit Choose... Firms can earn a loss Choose...Choose... Choose.. both short run and long run ket short run neither short or long run long run