Her poetry is always easy and __________.
One learns a language by making mistakes and ______ them.
By the time you have finished this book, your meal ______ cold.
—It’s a long time________I saw you last. —Yes,and what a pity it is now that it will be a long time________we see each other again.
The factory produces two million pairs of shoes every year, half _______ are sold abroad.
We should develop the sunshine project actively, because it can save _______ resources as well as reduce pollution.