The film Not One Less, ______ on a real story, is very instructive and well worth seeing.

In April,2009，President Hu inspected the warships in Qingdao，________ the 60th anniversary of the founding of the PLA Navy.

I still remember ______ to the Science Museum for the first time when I was young.

_______to sunlight for too much time will do harm to one’s skin. 

 .From the classroom window we saw a huge snake _____ the yard.