【单选题】关于时间序列的速度指标,下列说法正确的是( )。 A. 平均发展速度是对各时期的定基发展速度求序时平均数 B. 各时期环比增长速度的连乘积等于定基增长速度 C. 若两个相邻时期的环比发展速度相等,则这两个时期的定基发展速度也相等。 D. 定基增长速度等于累计增长量与基期水平之比。
【判断题】平均发展速度是各个时期环比发展速度的平均数。
【单选题】Which of the following statements about Bukuru market is INCORRECT?
A.
It is a large commercial area to the south.
B.
It was under military control.
C.
It was burnt to the ground.
D.
There were still debris and smoldering fires.
【单选题】下列关于对偶婚制的陈述中,不正确的有( )
D.
在相当长时期内,对偶婚制是和群婚制同时并存的
【多选题】下列陈述中,关于族外婚制的理解,正确的有()
B.
只有实行族外婚制,才能把一个氏族和其他氏族区别开来
【单选题】According to the passage, ______.
A.
security alarm systems can only be installed in commercial and industrial establishments and in large homes
B.
security alarm systems are still very expensive
C.
now, people can buy low-cost security alarm systems and install themselves
D.
security alarm systems can't scare off vandals
【单选题】At Seattle this year, the difference between America and the EU is over ______.