题干

果子酒放久了易产生沉淀,只要加入少量蛋白酶就可使沉淀消失,而加入其他酶则无济于事,这说明(   )

A:酶的催化作用具有专一性

B:酶的化学成分是蛋白质

C:酶的催化作用受环境影响

D:酒中的这种沉淀是氨基酸

上一题 下一题 0.0难度 选择题 更新时间:2012-08-01 07:51:52

答案(点此获取答案解析)

A

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根据短文内容,从短文后的选项中选出能填入空白处的最佳选项,选项中有两项为多余选项。

Planning a September trip to France

    September is one of the very best months to visit France.Not only will you enjoy plenty of sunshine and warm weather, but the tourist season is beginning to wind down—which means cheaper airfares, lower prices at hotels, and fewer crowds.____

●Go wine tasting

    ____And there are plenty of wine-related events and festivals around the country.So September is a great time to visit the vineyards around the country and go wine tasting.The Bordeaux, Loire and Burgundy regions are all lovely and great places to visit vineyards.Besides that, going to the castles of the Loire region in between visiting vineyards on such warm and Sunny days is also very enjoyable.

____

    The temperatures are slightly lower,but plenty of sunshine makes for perfect conditions to enjoy a barge cruise on the canals of France.With such comfortable weather and beautiful scenery at this time of year, nothing equals hanging out on the deck of a barge.

●Visit the museums

    Many museums in France have extended opening hours during the summer to accommodate the extra tourists and locals. And some museums also have extended opening hours into September.Wandering around the Louvre will take you into a wonder world,where you can enjoy the world-famous art.____

    Besides the above,riding a bike through France's villages is also a welcome activity for young visitors in September.You can shop for the most fashionable clothes or goods here.You can see the beautiful and fantastic scenery along the road.____

A.Take a barge cruise.

B.Enjoy the music concerts.

C.So, don't hesitate and start to plan your September trip to France flow!

D.France is a beautiful country.

E.September is the beginning of the grape harvest season in France.

F.Going out of the Louvre, you can walk to the modern and fashionable Champs Elysees to do some shopping.

G.If this is your first trip to France, here is some handy information to help you get started planning your vacation!