您要查找的是不是：
- This is a device for squaring the circle. 这是一个不可能实现的方案。
- I am well aware that this is a tough job. 我深知这是一件棘手的工作。
- This is a bewildering difficult problem, also be one makes a lot of scholars much some rarer feel depressed task. 这是一个令人困惑的难题,也是一个令许多学者多少有些感到沮丧的课题。
- This is a optimized algorithm about circle. 关于圆的一个优化算法
- This is a highly efficient new heating system. 这是个高效的新取暖系统。
- This is a sort of indeterminate color. 这是一种说不清的颜色。
- This is a coat of her own making. 这是她亲手做的外衣。
- This is a good place for a picnic. 这是一个野餐的好地方。
- This is a question that they have often debated. 这是个他们常讨论的问题。
- This is a task well within your ability. 这完全是你力所能及的工作。
- This is a very popular name for a girl. 这是一个非常普通的女孩名字。
- I certify that this is a true copy. 我证明这是真副本。
- This is a book for young and old (alike). 这本书老少咸宜。
- This is a kind of lavender-water. 这是一种熏衣草香水。
- This is a kind of metallic paint. 这是一种有金属光泽的涂料。
- This is a large passenger airliner. 这是一架大型客机。
- This is a plan for the fortification of the city. 这是一个加强城市防御的计划。
- You can't be leaving me this is a bad dream! 你千万不可离开我--这太可怕了！
- This is a fact hitherto unknown. 这是一个至今无人知道的事实。
- This is a block of undeveloped land. 这是块未开发的土地。
