So some rocks are radioactive because they have radioisotopes in their nuclei. Also they may have radon gas trapped in their crystals if they are igneous rock. They could also be radioactive due to the fact that the atom of the rock is unstable.
Connecting USB Devices Manually. Choose VM > Removable Devices to connect specific USB devices to your virtual machine. You can connect up to two USB devices at a time. If the physical USB devices are connected to the host computer through a hub, the virtual machine sees only the USB devices, not the hub.
When you map a virtual disk and its associated volume to a drive on the host system, you can connect to the virtual disk without opening a virtual machine. After you map the virtual disk to a drive on the host system, you cannot power on any virtual machine that uses the disk until you disconnect the disk from the host system. Note. You cannot map a virtual hard disk for a shared or remote virtual machine.