Bluewhalesarethelargestanimalseverknowntohaveexistedont...
問題詳情:
Blue whales are the largest animals ever known to have existed on the planet, and they can grow to a length of 100 feet and weigh more than 330,000 pounds. But recently researchers have found that these whales are on the move and they have migrated (moved) from California waters to areas off Canada and Alaska for the first time since commercial whaling ended in 1965.
The researchers identified 15 blue whales that have appeared off the coast of British Columbia and the Gulf of Alaska since 1997. Four of these whales were recognized as ones that were once sighted off California shores, suggesting that the whales are returning to an old migration pattern between the coasts.
Before commercial whaling began in the early 1900s, blue whales were found widely throughout the North Pacific and California waters. But from the 1920s to the 1960s, whaling severely reduced the whale populations. Blue whales never recovered in the Northern Pacific, making sightings in this area rare. However, much larger groups of whales have been observed close to California since the 1970s.
The scientists had previously thought that the California population was separate from the population that had historically lived in North Pacific waters. But the current study shows that whales off the coast of British Columbia and the Gulf of Alaska are likely part of the California population.
To identify the blue whales, the researchers looked at photos of cetaceans taken in the North Pacific Ocean and compared them with a library of blue whale pictures taken along the West Coast of the United States and Southern Pacific. Up to now, the researchers are not quite sure why the whales are changing their migration patterns, but they suspect that the whales may be following their food moving farther north by the changes in ocean conditions.
28. According to the passage, blue whales are __________.
A. following the fixed route of migration
B. dying out due to commercial whaling
C. rarely found in the Southern Pacific
D. moving from the south to the north
29. The whale population in the northern Pacific __________.
A. is different from the California population
B. has become the largest group since the 1970s
C. is probably part of the California population
D. has lived there since the 1960s.
30. The underlined word “cetaceans” in Paragraph 5 probably means __________.
A. whales species B. land creatures
C. ocean conditions D. migration patterns
31. What might make blue whales migrate according to the researchers?
A. Commercial whaling. B. Food resources.
C. Weather conditions. D. Life reproduction.
【回答】
DCAB
知識點:科普環保類閱讀
題型:閱讀理解
-
_____________,_____________。萬里悲秋常作客,百年多病獨登臺。杜甫《登高》
問題詳情:_____________,_____________。萬里悲秋常作客,百年多病獨登臺。杜甫《登高》【回答】無邊落木蕭蕭下,不盡長*滾滾來。知識點:其他題型:填空題...
-
光明在低頭的一瞬 ...
問題詳情: 光明在低頭的一瞬 遲子建 ...
-
下列各組詞語中,沒有錯別字的一組是A.閒情逸致 聲名鵲起 意氣相投 金碧輝煌B.情隨事遷 隱約...
問題詳情:下列各組詞語中,沒有錯別字的一組是A.閒情逸致 聲名鵲起 意氣相投 金碧輝煌B.情隨事遷 隱約其辭 誇誇奇談 前赴後繼C.夢寐以求 百折不撓 聞過飾非 慘淡經營D.言簡意賅 言近指遠 伸張正義 良辰...
-
對於一定量的理想氣體,下列說法正確的是______。(選對一個給3分,選對兩個給4分,選對3個給6分。每選錯一...
問題詳情:對於一定量的理想氣體,下列說法正確的是______。(選對一個給3分,選對兩個給4分,選對3個給6分。每選錯一個扣3分,最低得分為0分) A.若氣體的壓強和體積都不變,其內能也一定不變 B.若氣體的內能不變,其狀態也一定不變 C.若氣體的...
相關文章
- It'slateeveninginthemiddleofthewinter.Thesnowisdeep,but...
- —Allthevolunteers(志願者)wereverytired,but ofthemtookares...
- “BESTPRODUCTWE'VEEVERSEEN”-THISREALLYWORKS-ONSALENOWNee...
- Thevolunteerswhohelpthehomelesschildrenbelievethatevery...
- Ifoverweightpeopleeatlessandtakemoreexercise,they’llso...
- TakeActionforaBetterWorld:VolunteersNeededSixmonths’pre...
- Expensiveandnewglovesallowchatterboxes(話匣子)totaketheter...
- ThenewsofHarperLee’ssecondnovelbroketheinternet.GoSetaW...
- 閱讀理解Wehaveaterribleschooltriplastweekend.Somestudentswe...
- ---Thestudentslookverytiredafterthesportsmeeting.---We...