【简答题】在诸多生态因子中,使生物的耐受性____或____极限时,生物的生长发育、生殖、活动和分布等直接受到限制,甚至死亡的因子,叫做____。
【单选题】For a self-sufficient producer, the production possibilities frontier
A.
is the same as the consumption possibilities frontier.
B.
is greater than the consumption possibilities frontier.
C.
is less than the consumption possibilities frontier.
D.
is always a straight line.
【判断题】刀开关由进线座、静触头、动触头、出线座、手柄等组成。
【判断题】进口配额制的种类主要包括关税配额、自动出口配额、国别配额和绝对配额。
【判断题】刀开关由进线座、静触头、动触头、出线座、手柄等组成。
【单选题】A relationship that shows the technological possibilities for an economy as a whole is called a
B.
utility possibilities frontier.
C.
production possibilities frontier.
【单选题】刀开关由进线座、静触头、动触头 、手柄等组成