John was saved because he was sent tohospital_______[ ]

I don’t know the reason _______ you were absent from the meeting, and I am not sure that someone will tell me the reason _______ you haven’t told me.

The old scientist devoted most of his time __________ the space science.

Jack is ill, so we’ll have no choice but to give the performance ______ him

ent at a Nevada middle school opened fire on campus, wounding two l2-year-old boys and__________ a math teacher.