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.
To use an attached USB device you need to have: 1  A USB OTG (USB On-The-Go) cable. 2  USB Host Mode drivers loaded on your device. 3  A version of the Android operating system loaded on that device that supports USB Host Mode.SB Host Mode support was introduced in Android version 3.1 (Honeycomb) , so if you have Android 3.1, or newer installed on your device then you should have the necessary support for it in your OS, Android 4 also adds additional USB and OTG support.