- Shall I ___ the window   open

- She ___ dressed.   is getting

- She ___ drive. She walks to work.   can't

- She didn't come to class ___.   yesterday afternoon

- She doesn't like ___ alone.   living

- She drove ___the garage   into

- Simon usually ___ to bed early.   goes

- Some barriers involve competition with other species. A dandelion seed may be carried by the wind to bare ground, and, if environmental factors are right, it may germinate. There is not much chance, however, that any individual seedling will survive. Most places that are suitable for the growth of dandelions are already occupied by other types of plants that are well adapted to the area. The dandelion seedling must compete with these plants for space, water, light, and nutrients. Facing such stiff competition, the chances of survival are slim According to the passage, very few dandelion seedlings survive because of:   Competition from· other species

- Some barriers involve competition with other species. A dandelion seed may be carried by the wind to bare ground, and, if environmental factors are right, it may germinate. There is not much chance, however, that any individual seedling will survive. Most places that are suitable for the growth of dandelions are already occupied by other types of plants that are well adapted to the area. The dandelion seedling must compete with these plants for space, water, light, and nutrients. Facing such stiff competition, the chances of survival are slim. The word slim in this passage is closest in meaning to:   unlikely

- Some organisms cross barriers with the intentional or unintentional help of humans, a process called invasion. An example is the New Zealand mud snail, which was accidentally brought to North America when trout from New Zealand were imported to a fish hatchery in the United States. It has caused extensive environmental damage in streams and rivers. In the invasive species' native environments, there are typically predators, parasites, and competitors that keep their numbers down, but in their new habitat, natural checks are left behind, giving the invaders an advantage over native species. Invasive species may spread so quickly that they threaten commercial, agricultural, or recreational activities. The author gives New Zealand mud snails as an example of:   an invasive species that was unintentionally transported to another habitat