From the Middle East the Chinese acquired a blue pigment—a purified form of cobalt oxide unobtainable at that time in China—that contained only a low level of manganese.
中国人从中东获得了一种蓝色颜料，这是一种当时在中国很难得到的纯净的氧化钴，这种颜料只含有少量的锰。
2
If that coordinate is at the given level or below, then the tile is coloured blue, otherwise it is left transparent.
如果那个点等于或低于给定的海拔高度，则那块贴图就标为蓝色，否则就还是透明的。
3
This was the first clue that out of sight, level with the window sill, was a writing desk, and that at this desk, on sheets of unruled paper in blue felt-tip pen, Samuel Menashe was writing poems.