There are some dangerous fish in the river, and I’ve warned Jack______ here.

Jack reached the company out of breath, only _______he was fired.

Do you think it’s a good idea to make friends with your students ? — ________,I do I think it’s a great idea

I had just stepped out of the bathroom and was busy drying myself with a towel ________ I heard thesteps.[ ]

The news has spread all over the country____________the spaceship succeeded in returning to the earth.[ ]