血中激素浓度极低，但生理作用却非常明显，这是因为（）A、激素的特异性很高 B、激素的

阅读下列材料，从所给的六个选项(A、B、C、D、E和F)中，选出符合各小题要求的最佳选项，并在答题卡上将该项涂黑。选项中有一项是多余选项。
The people below are going to make a trip in Australia. After the description of these people, there is information about six advertisements of organized tours A-F. Decide which tours would be most suitable for the person mentioned in descriptions 1-5 and then mark the correct letter (A-F) on your answer sheet. There is one extra paragraph about one tour which you do not need to use.
____小题1:Victor is fond of nature and adventure and he is making a study tour into geology in Australia. So he wants to make a whole day trip, enjoy the natural beauty and study geological phenomena as well.
____小题2: Vanessa is planning a short city tour of Sydney so that she can enjoy the highlights of the city and attend an important lecture given by Professor Brown Smith at 2:00 pm at the University of Sydney.
____小题3:Charlie and his friends are making their first journey in Australia. Having traveled around the city of Sydney, they plan to visit Canberra, the capital and political center of the country.
____小题4:Jenny, a European woman with her children is visiting her relatives in Australia. They want to relax themselves by enjoying the sunshine on the sandy beaches along the coast and have fun with dolphins.
____小题5: Mike and Susan are from Brazil. They have been traveling in Australia for a couple of days. This weekend, they would like to have a change and travel to the countryside to have some idea of Australia grape farming and wine producing instead of making city tours around.

A．City Highlights, Manly Beach, Northern Beaches Tour the highlights of Sydney, then cross the Sydney Harbor Bridge to Manly and the Northern Beaches. Capture the beauty and lifestyle of the harbor city from Gray Line’s specially selected vantage points. Departs: 8:30am Adult: $51.00 Returns: 11:50am Child:25.50

B．New Parliament House, National Museum,Australian War Memorial The nation’s capital---a purpose built city, ultra modern, with imposing architecture yet a rural charm of lakeside, gardens and open spaces. This hi-tech city is the seat of Parliament and home of superb national monuments, museums and galleries. Departs: 8:30am Adult: $110.00 Returns: 9:15pm Child:$55.00

C．Cuddle a Koala, Kangaroos, Harbour LuncheonCruise Observe and meet our unique native animals with ample opportunity to get to know the Cuddly Koala. Then enjoy a spectacular luncheon cruise on beautiful Sydney Harbour. You can choose between the Matilda Cruises Sailing Catamarans, the streamlined Captain Cook Cruisers or Magistic Cruises. Departs: 8:40am Adult: $115.00 Returns: 2:00pm Child: $57.50

D．Hunter Valley Wineries, Wine Tasting,Traditional Aussie Towns

 E. Port Stephens, Central Coast Beaches, NorthCoast, Dolphin Watching
 F. Jenolan Caves, Blue Mountains, AdventureCaves