If the North was anti-slavery, why would they give black soldiers jobs where they could get sick easily?

I supposed they lacked much choice, they may have been more used to such conditions due to past experiences or they may have been unaware of effects, they could be anti slavery but they may consider being a soldier as different to a slave

offline recommendation systems option b

because recommendation systems produce a list of two ways

1. through collaborative filtering

or

2. through content-based filtering