1 . Don’t make such a careless mistake again. Let that be a ________ to you.

A．message

B．stranger

C．system

D．lesson

2 . —I like the school library. It provide a quiet and comfortable________ for us to study in.
—I agree with you. I can also relax and calm my mind in it.

A．environment

B．condition

C．system

D．activity

3 . —What a _______! You should put the toy cars on the shelf.
—Sorry, Mum. I’ll do it at once.

A．value

B．pity

C．mess

D．system

4 . Don’t stand too close to North Americans. You’d better give them more personal ________.

A．time

B．system

C．space

5 . Social workers have opened hotlines to offer free ________ to those in need, especially to the teenagers.

A．systems

B．services

C．symbols

D．stations