拖动鼠标到未加下划线的蓝色字体上，出现附加注释框。点击加下划线的蓝色字体(例如多数图例后的三个圆点), 注释框停留在屏幕上。移开鼠标到未加下划线的图例上，则注释框消失。试一试吧，非常简单！
Endoplasmic reticulum (ER) is membraneous organelle that begins at the nucleus and is involved in the protein synthesis. These proteins are further transported into the Golgi body. To ER attach ribosomes (therefore the name "rough ER") which form complex with the mRNA. This complex synthesizes protein chains into the ER lumen. These proteins are further transported into the smooth ER which lacks ribosomes and then into the Golgi body.
