The short answer is: The scientist means that a dose of 20 mg per kilogram is enough to kill one half or fity percent of the animals used in the test. LD stands for leathal doseage. The 50 means 50 percent. Subsequently a dose of 20 mg per killogram has a lethal dose that will kill 50% of the test subjects.
P Waves are compressional and the fastest moving seismic wave
S waves are slower than P waves and they can only travel through solid rock. S waves move the particles it pushes through up and down or side to side.
I believe it is B. Destruction of cells by viral reproduction :)
Answer:
best conclusion lyfe cycle of dis plant is de plant is a gymnosperm nd de sporophtes is dominant phase