单选题 Questions 21-25 are based on the following passage:
Wood carving refers to the art of creating or decorating objects of wood by carving with a sharp, hand-held tool. This form of art has a history of over 1,000 years and a unique artistic style. The following is some introduction about wood carving in America.
Wood carving began as a necessity in America and developed into an art. Because of the lack of other materials, early settlers were forced to make tools and utensils out of wood. At first, these articles were whittled with a knife, but when pioneer craftsmen set up their primitive shops most of them were fashioned on a lathe--a machine which holds an object and rotates it while it is being shaped by a tool.
However, even after Massachusetts-born Thomas Blancard designed a lathe which could turn irregular shapes--an innovation that made possible mass production of gunstocks, shoe lasts, oblong and square wooden wares--craftsmen who could use knife and chisel skillfully were still in demand. Some found ready employment in shops of cabinetmakers, while others, carved decoy. Still others specialized in creating shop signs, ship figureheads, or in decorating interior woodwork. A few even accepted commissions to make busts of prominent citizens.

单选题 This passage most likely came from a longer work about early American______.

单选题 According to the passage, the first settlers used wood for their utensils and tools because it was______.

单选题 The passage suggests that the early shops for making tools were______.

单选题 Which of the following objects was an important woodworking tool used by early American craftsmen?

单选题 In the last sentence, the word "bust" most probably means______.