Calcium cyanamide is poisonous and irritating to the skin.氰氨化钙是毒性物质,对皮肤有刺激性.A new process, urea - calcium cyanamide method, for producing thiourea from urea and hydrogen sulfide is proposed.利用尿素和硫化氢等原料制备硫脲, 提出了尿素 - 氰氨化钙法...
这孩子的手太小,按不到钢琴上八度和音的键.The child's hands are too small to stretch to an octave on the piano.我们听到传来几下钢琴和音的声音.A few chords from a piano reached our ears.你认为这首歌过于欢快是因为通篇都是大三和音的缘故 吗 ?Do you think that this song sounds too...