What<br/>microstructures can be observed in Rhubarb powder? A: clusters of calcium oxalate B: vessels C: starch granules D: brown cells E: stone cells

The<br/>crude drug which has the effects of“moderating drug” is<br/>____. A: Rhubarb B: Clove C: Senna<br/>Leaf D: Licorice<br/>Root E: Ginseng