_______ on the American Civil War, the book attracted a large number of readers when it was published.
31. --______ one and a half days enough for the painting to be finished? --I don’t think it’s enough and only after _________ go on with it.
30. It was once called the Sea of Bamboo, but now only one fifth of the area ______ covered with bamboo, and sixty percent of other plants ______ taken the place of the bamboo.
29. When it rains, you cannot help but _______ your shoes wet.
28. The cloth _______ easily if ______ on a table.
27. --Why do you have a _______ look? --Because you almost _______ me out of life by your _______ mask.