题目内容
Scientists have found the gene that determines skin color.
The gene comes in two versions, one of which is found in 99 per cent of Europeans.The other is found
in 93 t0 100 per cent of Africans, researchers at Pennsylvania State University report in the latest issue of Science.
Scientists have changed the color of a dark - striped zebrafish (斑马鱼) to uniform gold by inserting a
version of the pigment (色素) gene into a young fish.As with humans, zebrafish skin color is deter-mined
by pigment cells,which contain melanin (黑色素).The number, size and darkness of melanin perpigment
cell determine skin color.
It appears that, like the golden zebrafish, light - skinned Europeans also have a mutation (变异) in the
gene for melanin production.This results in less pigrnented skin.
However, Keith Cheng, leader of the research team, points out that the mutation is different in hu-man
ancl zebrafish genes.
Humans acquired dark skin in Africa about l.5 million years ago to protect bodies from ultra - violetrays of the sun. which can cause skin cancer.
But when modem humans leave Africa to live in northem latitudes, they need more sunlight on their
skin to produce vitamin D. So the related gene changes, according to Cheng.
Asians have the same version of the gene as Africans, so they probably acquired their light skin through the action of some other gene that affects skin color, said Cheng.
The new discovery could lead to medical treatments for skin cancer.lt also could lead to research in-to ways to change skin color without damaging it like chemical treatment did on Michael Jackson.
B. prove the humans' skin color is determined by the pigment gene
C. find out the reason why the Africans' skin color is dark
D. fincl out the ways of changing people's skin color
caused by the chemical treatment
B. Europeans and Africans have the same gene
C. the new discovery could help to find medical treatments for skin cancer
D. there are two kinds of genes
B. the new discovery could lead to research into ways to change skin color safely
C. pop king Michael Jackson often changed his skin color as he liked
D. people can not change their skin color without any pain
B. light - skinned Europeans have mutation in the gene for melanin production
C. they have fewer activities outside
D. they pay much attention to protecting their skin
B. negative
C. indifferent
D. positive
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Dining, Sightseeing and Special Events
Get on board to experience Vancouver from a different perspective (视角). Join Harbour Cruises Ltd.
For Vancouver's only guided tour of the inner harbour, the always popular dinner cruise (乘船巡游), or a
luncheon cruise through a quiet coastal mountain bay (海湾). Special event cruises are available throughout
the year including during the yearly fireworks competition and December's Christmas Carol Ships. Harbour
Cruises Ltd. is located next to world-famous Stanley Park. Dates of Operation: April-October and December
Seasonal Hours: 8: 00 am - 7: 00 pm, 7 days a week Directions: Drive west on Georgia and turn right at the
lights at Denman Street. Take the # 135 Stanley Park bus or walk west along Georgia for 15 minutes towards
Stanley Park from downtown.
Information: 604.688.7246
Reservations (预订): 1. 800. 663. 1500
Website: www. boatcruises. corn
Email: tours@boatcruises. corn # 1, North Foot of Den-man Street, Vancouver, BC V6G 2w9
The Lookout at Harbour Centre Tower
Not sure where to start? The Lookout,which is high atop Harbor Center Tower,is your best first choice
in Vancouver.Majestic cruise ships,mountains sprinkled with fresh snow and a west coast sunset are but
a few highlights of this grand 3600 view.Drink your cappuccino,join a free guided tour,learn something
new about Vancouver and enjoy the view!
Dates of Operation:Open 365 days/year
Seasonal Hours:Winter 9:00 am - 9:00 pm Summer 8:30 am - 10:30 pm
Directions:Located downtown at the SeaBus and SkyTrain station.
Just steps away from the Cruise Ship Terminal and historic Gastown.
Infonnation and Reservations:604.689.0421
Website: www. vancouverlookout.com
Email: info@vancouverlookout.com 555
West Hastings Street, Vancouver, BC V6B 4N4
Burnaby Village Museum And Carousel
Step back in time to 1925. The museum features a village, a farmhouse and the historic CW Parker
Carousel. Costumed townspeople welcome you to exhibits that include a schoolhouse, a blacksmith, a
Chinese medicine store and an ice - cream parlour.
Seasonal Hours: May 4 - Sept 2 (11: 00 am - 4:30 pm )
Christmas Hours: Nov 23 - Dec 13 & Dec31 - Jan 4(12:00 - 5:30 pm) and Dec 14 - 30 (12:00 - 8:00
pm) Closed Dec 24& 25
Directions: Take exit 33 from Hwy 1 to Canada Way. Follow the signs along the sidewalk to Deer Lake
Park. 20 minutes from downtown Vancouver.
Information: 604. 293. 6501
Telephone: 604. 293. 6500
Website: www. city. burnaby.cb.ca. 6501 Deer Lake Avenue, Burnaby, BC V5G 3T6
B. Harbour Centre Tower
C. Burnaby Village Museum
D. Stanley Park
information on _______.
B. Email: info@vancouverlookout.com
C. Website: www.city.burnaby.cb.ca
D. Website: www.boatcruises.com
B. There is fresh snow at Harbor Center Tower for people to enjoy.
C. Harbour Cruises LTD is closer to downtown than Burnaby Village Museum.
D. The ice - cream parlour provides you local delicious food at lunch time on Christmas Day.