2. Cassiterite is an ore of ______________________.
3. The blood pressure is denoted as following?
[A]Venous pressure/Pulse pressure
[B]Diastolic pressure/Systolic pressure
[C]Systolic pressure/Diastolic pressure
[D]Venous pressure/Systolic pressure
4. Who proved that bacteria does not originate by spontaneous generation?
5. Most part of the cosmic rays that impinge on earth's atmosphere are _____________________.