以下关于动机和行为效率的关系,描述正确的是()。
A. 动机越强,行为效率越高
B. 动机越弱,行为效率越高
C. 一般而言,中等动机水平,行为效率最高
D. 最佳动机水平与要完成的任务难度有关
Premodifiers and postmodifiers are classified based on their different __________.
A. functions
B. positions
C. structures
D. parts of speech
If a modifier only offers some explanation and without it the meaning of the whole phrase is not affected, this modifier is___.
A. postmodifier
B. restrictive modifier
C. nonrestrictive modifier
D. transferred modifier
选择恰当的词将句子补充完整。In the Middle Ages ______ believe in witches.
A. one
B. ones
C. people
D. men