题干

中国科学院某研究小组设计了一种高性能锂空气电池,其反应原理可表示为:2Li+O2 MnO2__ Li2O2,已知锂元素在化合物中显+1价,下列说法错误的是(   )

A:反应物锂是金属单质

B:该反应中MnO2是催化剂

C:Li2O2中氧元素的化合价显﹣2价

D:该反应是化合反应

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答案(点此获取答案解析)

C

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    The value-packed, all-inclusive sight-seeing package that combines the best of Sydney's harbour, city, bay and beach highlights.

    A SydneyPass gives you unlimited and flexible travel on the Explorer Buses: the 'red' Sydney Explorer shows you around our exciting city sights while the ‘blue' Bondi Explorer visits Sydney Harbour bays and famous beaches. Take to the water on one of three magnificent daily harbour cruises (游船). You can also travel free on regular Sydney Buses, Sydney Ferries or CityRail services (limited area), so you can go to every corner of this beautiful city.

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SydneyPass Fares


Adult

Child*

Family**

3-day ticket

$90

$45

$225

5-day ticket

$120

$60

$300

7-day ticket

$140

$70

$350

    *A child is defined as anyone from the ages of 4 years to under 16 years. Children under 4 years travel free.

    **A family is defined as 2 adults and any number of children from 4 to under 16 years of age from the same family.