—What are you doing? —I'm      the key to the door.

A. finding out       B. looking after    C. looking for

—What are you doing?
— I’m looking ___ the children. They should be back for lunch.

A．after

B．at

C．for

D．up

—What are you doing? —I'm     the key to the door.
A. finding out       B. looking after    C. looking for

---What are you looking for?
---I’m looking for the book ________ you lent me yesterday.
A. that   B. who   C. whose

—What are you doing?
—I'm     the key to the door.
A. finding out       B. looking after    C. looking for