Like all animal species, plant species must spread their offspring to suitable areaswhere they can grow and pass on their parent’s genes. Young animals generally spread (1) ______by walking or flying. Because plants don’t have that ability, they may somehow (2) ______hitchhike. Some plant seeds scatter by blowing in the wind or floating on water. Many other plant species, though, trick an animal into carrying their seeds. How dothey do They enclose them within a tasty fruit and advertise the fruit’s ripeness byits color or smell. The hungry animal collects and swallows the fruit, walks orflies off, but later spits out the seeds somewhere far from its parent tree. Seeds (3) ______can thereby be carried thousands of miles. It may surprise you to learn that plant (4) ______seeds can resist digestion. In fact, some seeds actually require passage through ananimal’s body before they can grow. Wild strawberries offer a good example ofhitchhiking tactic. When strawberry seeds are still young and not yet ready to be (5) ______ planted, the surrounding fruit is green, sour, and hard. When the seeds final mature, (6) ______ the berries turn red, sweet, and tender. The change in the berries’ color serves asa signal to birds which then eat the strawberries, fly off, and eventually spitout the seeds. Naturally, strawberry plants doesn’t set out with a conscious intent (7) ______of attracting birds only when their seeds were ready to be dispersed away. Nor (8) ______did birds set out with the intent of planting strawberries. Rather, strawberry plantsevolved through natural selection. The sweeter and reder the final strawberry, the (9) ______more birds spread its ripe seeds; the greener and more sour the young strawberry,the birds destroyed the seeds by eating berries before the seeds were ready. (10) ______