题干
We will never forget those happiest days _______ we spent on the summer camp.
A：which
B：that
C：when
D：on which
答案(点此获取答案解析）
B
We will never forget those happiest days _______ we spent on the summer camp.
A：which
B：that
C：when
D：on which
Ⅱ，已知状态Ⅱ的温度高于状态Ⅰ的温度。若气体分子之间的相互作用力在不发生碰撞时可以忽略不计，则在这些状态变化过程中