YDS 2018-1 Soru=78

(I) The best conditions for dandelion seeds are relatively
calm, sunny days that generate thermal updraughts.
(II) A 2003 study at the University of Regensburg in
Germany found that 99.5 percent of dandelion seeds
land within 10 metres of their plant. (III) That is because
the seed 'parachute' falls at about 30 cm per second
and dandelions only grow about 30 cm high. (IV) So, that
gives each seed just one second of flight time to be
blown sideways by the wind to its new home. (V) Higher
wind speeds do not really increase the distance the
seeds fly, because strong winds tend to blow
downwards as well as sideways, so the seeds just land
even sooner.