Harvester ants often strip a bush of all of its leaves. Some people believe this helps the plant grow thicker, healthier stems. In an experiment, a student stripped off all the leaves from a set of plants. In a second set of identical plants, the student allowed ants to strip off the plants' leaves. In order to improve this experimental design, it is most important to add a set of plants :

a. with the same amount of water
b. of different species
c. with their leaves on
d. with different species on ants on them

What came first the elephent or the crocodile

1. emigration the movement of people from one place to another 2. immigration a situation in which resources are being used up at a faster rate than they can be replenished 3. migration the leaving of one's homeland to settle in a new place 4. overpopulation the movement of people to a new country 5. sustainable development a situation in which the birth rate is not sufficient to replace the existing population 6. underpopulation the ability to meet current needs without reducing the ability to meet future needs 7. unsustainable development the increase in the population of a city 8. urbanization a situation in which the number of people exceeds the available natural resources in an area

How can active reading strategies you? o a. they can you get into better physical shape. o b. they can you read fewer science articles. o c. they can you understand what you read. o d. they can you avoid reading altogether.