下列成就中不属于“863计划”成果的是（    ）

    My mother is a teacher. On weekdays, she gives lessons at school and on Saturdays she works in clubs. On Sundays, she is still busy.

On Sunday morning, mum gets up at six. She cooks breakfast for us first. And then it's time for cleaning. After that, she has breakfast with father and me. At 9, she goes to buy food for lunch in the supermarket. She can have a short rest after lunch. In the afternoon, mum doesn't go out. She helps me with my lessons. She does some reading, too.

    Mother watches TV at about 7 when she finishes (完成) the housework. But at that time she is always tired and falls asleep (睡着) in the sofa sometimes.

  2003年10月27日～31日，我国北方地区大多数的居民，在日出后的一段时间内用肉眼可清晰地看到太阳黑子这一奇观．据此判断下题．

下列各几何体中，直棱柱的个数是（    ）