问题
选择题
Scientific research shows that animals can show emotions like human beings. They are sometimes lively, and sometimes bad-tempered.
A．contradictory
B．instant
C．appropriate
D．flexible
答案
答案：D
题目分析：考查形容词。A．contradictory矛盾的；B．instant立即的；C．appropriate适当的；D．flexible灵活的。句意：科学研究表明，动物可以显示像人类一样灵活的情感。它们有时活泼，有时坏脾气。故D正确。