Question

building dams to help people
texas has several major rivers. they usually flow peacefully toward the gulf of mexico. in the late 1900s
when it would rain a lot, the rivers became problems. the
rivers would overflow their banks. they became raging
flood waters. homes and businesses were flooded and many
lives were lost.
thats when texans decided to build huge dams
across many of the rivers. during a heavy downpour of
rain, the dams would stop the flow of water. after the rains,
the water could be released in small amounts at a time.
then, flooding would not occur as much. this saved millions
of dollars spent on cleaning up after floods.
the water that collects behind a dam forms a
beautiful lake. one example is lady bird lake in austin,
texas.
texas has long, dry summers. sometimes there is
very little rainfall for several months. these dry periods
are called droughts.
the dams are helpful during droughts, too. water can
be pumped from the lakes formed by the dams. the water is
used by people who live in the area.
people change their environment. they change it so
they can survive. they change it so they can be more
comfortable. building dams is an example of how people
change their environment. by building dams, they have
solved the problems of flooding. by creating lakes, they
have solved the problem of not having enough water during
droughts.

1. the purpose of paragraph 1 is to ___.

a. tell why dams are harmful to the environment
b. explain how people change the environment to build dams
c. explain the problem that people were having with flooding
d. entertain the reader with a story about a river that floods

1. the central idea of paragraph 2 is that ___.

a. dams help provide water during drought periods
b. major rivers flood during rainy seasons
c. texans built dams across rivers to prevent flooding
d. clean - up after floods can cost millions of dollars

1. a dam prevents flooding by ___.

a. allowing water to flow down the rivers during rains
b. stopping the flow of water during rains
c. releasing water into rivers during heavy rains
d. providing water for people to use in their homes

1. explain two benefits of building dams.

Explanation:

1. Paragraph 1 describes rivers flowing to the Gulf of Mexico causing problems (flooding when there's a lot of rain). People built dams to change this situation (as dams could stop flooding). So it's explaining how people change the environment to build dams.
2. Paragraph 2 talks about Texans building dams. When there is heavy rain, the dams can stop the flow of water (by not releasing too much at once). During drought, water can be pumped from the lakes (formed by dams) for use. So dams help provide water during drought (option C: major rivers flood during rainy seasons - no, dams prevent that; option B: Texans built dams across rivers to prevent flooding - yes, but the main idea is about providing water in different times; option A: dams help provide water during drought periods - correct as the text mentions water can be used from the lake (dam - formed) during drought.
3. Dams form lakes. During rain, water is stored (so it doesn't flood as much - stopping the flow during rains). During drought, water is pumped out (allowing water to flow down the rivers for use). So a dam prevents flooding by stopping the flow of water during rains (option B).
4. Benefits:

• Flood prevention: As in paragraph 2, when there is heavy rain, the dams can control the water release. For example, "the water could be released in small amounts at a time" during heavy rains (so it doesn't flood).
• Water supply during drought: "Water can be pumped from the lakes formed by the dams" during droughts (as mentioned in paragraph 3).

Answer:

1. B. explain how people change the environment to build dams
2. A. dams help provide water during drought periods
3. B. stopping the flow of water during rains
4. Two benefits: flood prevention (by controlling water release during heavy rain) and water supply during drought (by pumping water from dam - formed lakes).