题干

下列关于精子与卵细胞结合成合子过程的叙述,正确的是
①合子中的遗传物质主要来自染色体
②合子中的细胞质主要来自卵细胞
③受精时精子全部进入卵细胞中
④精子和卵细胞的染色体合在一起,数目变为4N
⑤合子中的染色体一半来自父方,一半来自母方

A:①②⑤

B:③④⑤

C:①③④

D:②③④

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A

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                                                                                 World's Wonderful Libraries

    How cool can libraries be in an era of iPads and Kindles Morethan you think. Only if you know where to go.

                                                                                         Central Library

    The Central Library in Seattle,United States is modern and sophisticated. The building is an impressive work of art, which has tourists from around the world paying visits and taking tours. The library offers free self-guided cell phone tours, along with group tours.

    The library holds various art exhibitions, book signings andother events throughout the year.

    Open: Monday-Thursday 10 a.m-8 p.m, Friday-Saturday 10 a.m-6p.m, Sunday noon-6 p.m

                                                                                      Trinity College Library

    The Trinity College Library in Dublin is the oldest library in Ireland, founded in 1592 by Queen Elizabeth I.

    Not only is the exterior impressive, it boasts the largest single chamber library in the world, also known as the Long Room, which contains more than 200,000 of the library's oldest books.

    Various exhibitions and tour are available; admission 9(US 12)

    Open: Monday-Wednesday 9:30 a.m -5 p.m, Tuesday 9:30 a.m -9 p.m,Saturday 9:30 a.m -1 p.m, Sunday closed.

                                                                                    Bibliotheca Alexamdrina

    The Bibliotheca Alexamdrina is the revival(复兴) of theancient Royal Library of Alexandria, which was the largest and most influential library in the Greek world. It was built by Alexander the Great some 2, 300years ago.

    The new library was reborn in 2002 on the shore of the Mediterranean Sea after 10 years of designing, planning and construction.

Along with the standard libraries, there are four museumscovering science, Arabic Calligraphy, the history of printing and the Greekart.

    Open: Saturday-Thursday 9 a.m- 4 p.m.

                                                                                       Stuttgart City Library

    The Stuttgart City Library is controversial. Some say it's innovative, while others say it doesn't match its environment.

     Nevertheless, the library is one of the most interesting buildings in Germany. The design of the cubic facility was influenced by the ancient Pantheon in Rome. It serves as a multi-story meeting space that draws natural sunlight through the roof.

    Open: Monday-Saturday 9 a.m--9 p.m