Q1. Why can both 2,000 and 8,000 be right?

1. ABecause the number depends on what you want to do
2. BBecause all English words are easy
3. CBecause dictionaries are different
4. DBecause people forget words

Both can be right. It depends on what you want to do. とあるので A。

Q2. How many word families may you need to enjoy novels without a dictionary?

1. AAbout 600
2. BAbout 2,000
3. CAbout 3,000
4. DAbout 8,000 to 9,000

to enjoy novels without a dictionary, you may need about 8,000 to 9,000 とあるので D。

Q3. Which is an example of one word family?

1. A"cat," "dog," and "bird"
2. B"happy," "happiness," and "unhappy"
3. C"run," "swim," and "jump"
4. D"red," "blue," and "green"

A word family is a group like "happy," "happiness," and "unhappy." とあるので B。

Q1. What is "lexical coverage"?

1. AThe number of books you have read
2. BThe speed at which you read
3. CThe percentage of words in a text that you know
4. DThe size of your dictionary

lexical coverage, the percentage of words in a text that you know と説明されているので C。

Q2. At 98% coverage, how many words are unknown?

1. AOne in 20
2. BOne in 50
3. COne in 98
4. DOne in 8,000

At 98%, only one word in 50 is new. とあるので B。

Q3. What can we infer from the passage?

1. AReading generally needs more vocabulary than everyday listening.
2. BListening needs more words than reading.
3. CEveryone needs exactly 2,000 words.
4. DCoverage has no effect on understanding.

書かれた文章は8,000〜9,000語族、日常的なリスニングは2,000〜3,000語族で対応できる場合もあることから A。

Q1. According to the passage, why do the two claims only seem contradictory?

1. ABecause one of them is simply false
2. BBecause they depend on the learner's goal and the target coverage level
3. CBecause native speakers know fewer words
4. DBecause conversation uses more words than reading

Both can be defended once two things are fixed, the learner's goal and the target level of lexical coverage とあるので B。

Q2. What did Laufer and Ravenhorst-Kalovski propose as a minimal threshold for reading?

1. A98% coverage
2. B90% coverage
3. C95% coverage
4. D100% coverage

proposed 95% ... as a minimal threshold for reading and 98% as an optimal one とあるので C。

Q3. Why should the estimates be treated with some caution?

1. AThey change depending on how words are counted and how proper nouns are treated.
2. BThey were based on only one novel.
3. CNative speakers did not agree with them.
4. DThey apply only to Japanese learners.

All of these figures move considerably depending on whether words are counted as word families or as individual forms, and on how proper nouns are handled とあるので A。