单选题
Which of the following is the smallest in size?
A．Viruses．
B．New filters．
C．Living cells．
D．Chemical molecules．
推理题。题干意为“以下几个选项中，哪个是尺寸最小的?”。根据文章倒数第二段最后一句“…larger than the largest chemical molecules and smaller than the smallest living things．”可知，通过三者的比较，应该是chemical molecules最小。故D为正确答案。
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1
根据下面资料，回答题。
Good Value Britain
TRAVELING IN SCOTLAND
Scotland Travelpass gives you the freedom to use trains, buses and boats in Scotland as much as you like for a fixed period of time, at any time. The pass comes in a helpful pack, with timetables and maps along with discount cards, and is available for either four days (￡89) or eight days(￡119).
For more details, visit www. scotral, co. uk or, in the UK, Tel: 08457550033
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The capital offers a host of .sights, experiences and wonderful memories and one of the best money-saving plans is the London Pass. This allows you free entry for more than 60 attractions.
When you buy the card you receive a 132-page colour guidebook and information on the latest built-in discounts on restaurants and tours. You can also have fast track entry at some of the busiest at-tractions, to jump those lines. Passes are available for one to six days or you can include a travel pass for public transport within zone 1-6 for ￡82. Order your pass on the credit card line, Tel:
(UK) 08702429988, or buy online at www. londonpass, com.
The London for Less discount card comes in a pack with guidebook and a handy fold-out street map. For ￡ 12.95 London for Less gives you discounts, from 20-50%, at more than 300 different London attractions, including shows, concerts and restaurants. You can also get discounts on eve-rything from clothes to money exchange. You can buy your London for Less card from some major bookshops in the capital.
BRITAIN´S HERITAGE FOR FREE
The Great British Heritage (GBH) Pass gets you into 600 of Britain´ s finest historic houses,castles and gardens and is available for four, seven,15 days or a month. This year even more at-tractions are open to GBH cardholders. Visit www. visitbritain, com or go to the Britain Visitor Centre for more information.
With Scotland Travelpass，you can__________．
A．use Internet service
B．buy discounted maps
C．have free use of public transport
D．enjoy free entry to many museums
2
One use ofthe London Pass is to __________．
A．save you from waifing at some tourist sights
B．offer you free bus rides throughout London
C．enable you to shop online with discounts
D．guide you to London’s best restaurants
