题目

   There are desert plants which survive the dry season in the form of inactive seeds. There are also desert insects which survive as inactive larvae (幼虫). In addition, difficult as it is to believe, there are desert fish which can survive through years of drought (干旱) in the form of inactive eggs. These are the shrimps (虾) that live in the Mojave Desert, an extremely dry place in the southwest of the United States where shade temperatures of over 50℃ are often recorded. The eggs of the Mojave shrimps look like grains of sand both in size and appearance. When enough sprin下列命题中，假命题是（　） A．过一点有一条直线与已知平面垂直 B．过一点只有一条直线与已知平面垂直 C．过一点有且只有一条直线与已知平面垂直 D．过一点可以有两条直线与已知平面垂直