The peaks of the island are frequently obscured by clouds. Pinatubo was heavily eroded, inconspicuous and obscured from view. Offensive words may be partially obscured or bleeped. As they flew through the Andes, clouds obscured the mountains. Critics contend that such disenfranchisement is partially obscured by the Electoral College. Brant's face is partially obscured on the front cover. The house number is also partially obscured. Dresden was also obscured by clouds, so the groups targeted the city using H2X. If clouds obscured Dresden but Chemnitz was clear, Chemnitz was the target. The memory of the Prague Spring is thus largely obscured and often overviewed. Optical photons can be obscured or diffused by dust, gas, and background radiation. These may be partially obscured by track skirts, of which the Merkava Mk. Pointer balloons indicate objects that might otherwise have been obscured. The man's face is largely obscured by a hovering green apple. The subsequent events are obscured by conflicting accounts.