The second book _______ you are reading is written by an American novelist.
My father did not go to New York; the doctor suggested that he ___ there.
Neither Jack and Tom ___ Mary ___ at home that day.
The River Nile ___ flood large areas, but now the water of it ___ produce electricity.
We learned a lot from her father, an engineer ___ does research ___ science.
You should make a careful plan ___ the experiment.