1. means (p. 242, line 9)

Sentence: ….because farm chores had to be completed mostly by MEANS of manual labor by the farmer and his familyMeaning: a method, system, object, etc. that is used a way of achieving a resultPronunciation: /minz/Expression: by means ofPart of speech: nounGrammar of the word: plural only

2. productive (p. 242, line 6)

Sentence: Farmers in the 1900s were not able to be as PRODUCTIVE as farmers of today.Meaning: producing or achieving a lotPronunciation: /prə‘dʌktɪv/Antonym: unproductivePart of speech: adjectiveNoun form: productivity [U] Verb form: produce [T]Adverb form: productively

3. adapt (p. 19, line 6)

Sentence: Living beings who spend all of their time at high altitudes are able to ADAPT to shortages of oxygen.Meaning: to change something so that it is appropriate for a new purpose or conditionPart of speech: verbGrammar of the word: transitivePronunciation: /ə’dӕpt/After the word: infinitive OR “for” + nounNoun form: adaptation [U]Adjective form: adaptable

4. shortage (p. 19, line 6)

Sentence: Living beings who spend all of their time at high altitudes are able to adapt to SHORTAGES of oxygen.Meaning: a situation in which there is not enough of something that people needPart of speech: nounGrammar of the word: countable & uncountablePronunciation: /‘ʃɔrțɪʤ/After the word: “of” + nounAdjective form: short [of]

5. drop (p. 491, right column, line 6)

Sentence: This is quite a DROP from the 40 percent of the population that was involved in agriculture in 1900.Meaning: a decrease in the amount, level, or number of somethingPronunciation: /drap/ Grammar of the word: singularPart of speech: noun Verb form: drop [T,I] dropped, dropping