根据句意及首字母提示补全单词.

1.Let's c_______ Liu Xiang on.

2.Work hard, and your f_______ is not a dream.

3.Things are looking p_______ good.

4.The Big Big World is a very p_______ song.

5.My grandma is old. There is something wrong with her h_______.

一定温度下，将2mol PCl₃和 1mol Cl₂充入容积不变的密闭容器中，在一定条件下反应：PCl₃+Cl₂PCl₅。各物质均为气态。达平衡后，PCl₅为0.4mol。若此时再移走1mol PCl₃和0.5mol Cl₂，相同温度下达到平衡，PCl₅的物质的量为（　　）

A．0.4mol

B．0.2mol

C．0.2<x<0.4mol

D．<0.2mol