1 but,favourite eating varieties like cod and skate which grow to unnatural sizes.grow后面加个to什么意思？2,Three factors have caused these fish to grow so large .grow前面为什么加to3.the plentiful supply of food thrown overboard by the crews on the rigs。为什么用overboard什么意思？

1 but,favourite eating varieties like cod and skate which grow to unnatural sizes.grow后面加个to什么意思？
2,Three factors have caused these fish to grow so large .grow前面为什么加to
3.the plentiful supply of food thrown overboard by the crews on the rigs。为什么用overboard什么意思？