Cutting an Unfocused Sentence from a Science Report
Read this draft introduction a student wrote for a report on city trees:
(1) Cities are often several degrees hotter than nearby rural areas. (2) This happens because concrete and asphalt absorb heat during the day and release it slowly at night. (3) Many cities now plant trees along sidewalks and in small parks. (4) Trees cool the air by shading surfaces and by releasing water vapor through their leaves. (5) Some trees also produce fruit that residents can pick. (6) The shade from a mature tree can lower the temperature of the pavement beneath it by more than 10 degrees.
The student wants the paragraph to explain one main idea: how trees reduce urban heat. The report is for a science class, and the student has been told to cut any sentence that does not support the main idea.
1. Which sentence should be removed, and why?
Read the worked answer
Sentence (5) should be removed. The paragraph's main idea is how trees reduce urban heat. Sentences (1)–(2) set up the heat problem, (3) introduces tree planting as a response, (4) explains the cooling mechanisms, and (6) gives a concrete measurement of cooling. Sentence (5), about fruit, is a different benefit of trees. Keeping it would turn the paragraph into a general list of tree benefits and weaken the single explanation the student was asked to give.
2. The student wonders whether moving sentence (6) to follow sentence (4) would improve the paragraph. Evaluate that change.
Read the worked answer
Yes, moving (6) directly after (4) would improve the paragraph once (5) is removed. Sentence (6) supplies evidence for the claim in (4) that shade lowers surface temperature, so placing the evidence immediately after the claim keeps the explanation tight. If (5) were kept, (6) would still work better before (5) than after it, because otherwise the fruit sentence would separate the evidence from the claim it supports. The strongest order is 1-2-3-4-6.