如果使用得当，避孕套是很有效的避孕手段。Condoms are an effective method of birth control if used with care.有些人指控税务稽查员使用了流氓手段。Some people accuse the tax inspectors of bully-boy tactics.那些熟悉桑德斯的人都称他为手段高明的政治家。Those familiar with Sanders call h...
前质体能分化成各具特点的细胞器,如淀粉体, 叶绿体和有色体.The proplastids differentiate to form characteristic organelles such as amyloplasts, chloroplasts and chromoplasts.淀粉体:一种与合成和储存淀粉粒有关的质体.Amyloplast A plastid that synthesizes and stores starc...
In those days, dentistry was basic. Extractions were carried out without anaesthetic.那时候，牙科学刚起步，拔牙都不打麻药。His work was important in helping establish dentistry as a separate profession.他在推动牙医学发展成一门独立学科的过程中发挥了重要作用.Health Sc...