【简答题】元素周期表是学习和研究化学的重要工具.在周期表中原子序数分别为1、6、8、11的元素为H、C、O、Na,请选用其中的元素写出符合要求的化学式一个 (1)常温下为气态的非金属氧化物 ______. (2)由三种元素组成的碱 ______. (3)由四种元素组成的盐 ______. (4)能用于实验室制O 2 ,且原子个数比为1:1的物质 ______.
【单选题】以下哪一种目光注视方向表示尊重与期待,适用于面对尊长之时
【单选题】100多个国家签署生物与毒素武器公约的时间是
【判断题】Angle modulation can provide better discrimination against noise and interference than AM modulation.
【单选题】Racial discrimination will breed the anger that can a whole society.
【单选题】Which statement can be inferred from this passage?
A.
Racial discrimination originated from the attempts of each race to keep its identity.
B.
Despite the racial discrimination, all the people are helping America develop.
C.
Indian should not be so superior.
D.
The blacks suffer from the worst crimination now.
【单选题】Price discrimination
A.
a. is illegal in the United States and Europe.
B.
b. can occur in both perfectly competitive and monopoly markets.
C.
c. is illogical because it does not maximize profits.
D.
d. can maximize profits if the seller can pr the resale of goods between customers.
【简答题】当代德育理论中流行最为广泛、占据主导地位的德育学说是道德教育的( )。
【单选题】以下哪一种目光注视方向表示尊重与期待,适用于面对尊长之时。
【单选题】直接位于沥青面层下由不同材料铺筑的主要( )层称做基层。