Answer:
5. Fifteen kilometers <em><u>is</u></em> a nice distance to ski in an afternoon.
6. Analyzing sentences for grammatical purposes <em><u>is</u></em> even better than watching paint dry.
7. Economics <em><u>is</u></em> almost as fascinating as accounting.
Explanation:
The use of "is" or "are" depends majorly on the condition of the noun involved. This means that if the noun is singular, we use "is" while for plural nouns, we use "are".
In the given sentences, "is" and "are" are used as follows-
5. In this sentence, the distance "fifteen kilometers" is taken as a single unit even though the word "kilometers" is in the plural state. Thus, the helping verb will be "is".
6. Here, the verb "analyzing" is taken as a gerund, thereby functioning as a noun. And so, the helping verb used will be "is".
7. Similarly, this sentence contains the noun "economics" which is a branch of study and thereby taken as a singular noun. Thus, the verb will be "is".
Thus, in all three sentences, the helping verb used will be "is".
Answer:
Because he has trouble using them, and also has trouble being gentle.
Lady Macduff believes that her husband has abandoned her and her family, and is angry at him for doing so. She says "Whither should I fly? <span>I have done no harm." </span>She believes (and she is right) that she has done nothing wrong, so there is no reason she should try to run from her own house.
(3) Fire, in fact, has been a significant factor in human development and progress in many ways.
This is the main idea. The rest of the sentences support the idea that fire has helped human development and progress. It says that it has allowed humans to "travel into regions that were previously too cold" and "to sleep securely". The passage then continues to talk about how when humans learned to control fire it made significant changes in how long people were able to be productive since they no longer had to rely on the sun for light.
