Please remember _______ the plants while I’m away.
Thanks to Dr Yuan’s research, the UN has more tools in the battle to rid the world _____ hunger.
______ is even more important is that the earth cooled down, water began to appear on its surface.
Jane _____ these families of chimps for many years and helped people understand how much they behave like humans.
It is so wet there _____ the trees are extremely tall, some measuring over 90 meters.
Many _______ of years later, the first extremely small plants began to appear on the surface of the water.