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 connecting a USB printer to your computer, you must physically connect the printer to your computer and also electronically connect the device within Windows to the first available Virtual Printer Port â USB001 or USB002. If this is the only USB printer you are connecting to your computer, select USB001.