这个项目预计需要三周半的时间完成。

The project is expected to take ___three-and-a-half weeks to complete.

我儿子已经三岁半了，能自己穿衣服了。

My son is ___three-and-a-half and can dress himself now.

这部电影时长三个半小时。

The movie runs for ___three-and-a-half hours.