题干
Cathy was born blind（天生是盲的）, so she has __________ seen our beautiful world.
A：often
B：sometimes
C：seldom（很少）
D：never
答案(点此获取答案解析）
D
Cathy was born blind（天生是盲的）, so she has __________ seen our beautiful world.
A：often
B：sometimes
C：seldom（很少）
D：never
2Z(g) ΔH ＜ 0。下图表示该反应的速率（v）随时间（t）变化的关系，t2、t3、t5时刻外界条件有所改变，但都没有改变各物质的初始加入量。