操作中发现起升制动器失效，应立即把手板置于工作位置。
参考答案：错
简述沈从文散文集《湘行散记》和《湘西》的艺术特色。
Tim is in good shape physically（）he doesn't get much exercise.
A. if
B. even though
C. unless
D. as long as
