Answer the following question given this paragraph: Mountain streams may erode waterfalls. As shown in Figure below , a waterfall forms where a stream flows from an area of harder to softer rock. The water erodes the softer rock faster than the harder rock. This causes the stream bed to drop down, like a step, creating a waterfall. As erosion continues, the waterfall gradually moves upstream. Q: When a stream flows from a hard to soft rock area, what is often formed? Choices: - a lake - a river - a riverbank - a waterfall A:
a waterfall
(Question)
Answer the following question given this paragraph: Living in a large colony requires good communication. Ants communicate with chemicals called pheromones . For example, an ant deposits pheromones on the ground as it returns to the nest from a food source. It is marking the path so other ants can find the food. Honeybees communicate by doing a "waggle dance. ". Q: Living in a large colony requires good communication. ants communicate with chemicals called what? Choices: - alkalides - hormones - peptides - pheromones A:
(Answer)
pheromones
Ques: Answer the following question given this paragraph: The most basic division of modern plants is between nonvascular and vascular plants. Vascular plants are further divided into those that reproduce without seeds and those that reproduce with seeds. Seed plants, in turn, are divided into those that produce naked seeds in cones and those that produce seeds in the ovaries of flowers. Q: What types of living things are divided into nonvascular and vascular groupings? Choices: - organs - mammals - animals - plants A:
Ans: plants
(Q).
Answer the following question given this paragraph: Because isomers are different compounds, they have different properties. Generally, branched-chain isomers have lower boiling and melting points than straight-chain isomers. For example, the boiling and melting points of iso -butane are -12 C and -160 C, respectively, compared with 0 C and -138 C for n -butane. The more branching there is, the lower the boiling and melting points are. Q: Which type of isomers generally have lower boiling and melting points than straight-chain isomers? Choices: - straight-chain isomers - branched-looping isomers - branched - solar isomers - branched-chain isomers A:
(A).
branched-chain isomers
Ques:Answer the following question given this paragraph: Q: The water cycle involves movement of water between air and what? Choices: - tree - animals - air - land A:

Ans:land
Answer the following question given this paragraph: Sunlight contains the complete range of wavelengths of electromagnetic waves. The entire range is called the electromagnetic spectrum. Q: What do you call the entire range of wavelengths of electromagnetic waves? Choices: - electric spectrum - gaseous spectrum - molecular spectrum - electromagnetic spectrum A:
electromagnetic spectrum