一个四棱锥和一个三棱锥恰好可以拼接成一个三棱柱.这个四棱锥的底面为正方形，且底面边长与各侧棱长相等，这个三棱锥的底面边长与各侧棱长也都相等．设四棱锥、三棱锥、三棱柱的高分别为
，
，
，则
（ ）
A． |
B． |
C． |
D． |
He was educated at the local high school, ______ he went on to Beijing University.
| A．at which | B．after which | C．in which | D．during which |
_______, and we will do the work better.
| A．Give us more time | B．Given more time |
| C．Giving us more time | D．Having given us more time |
With just four years _______, the Brazil Olympic organizers have promised to deliver an equally inspirational ceremony.
| A．gone | B．to go | C．going | D．go |
________ seems to be no possibility _______ the shy girl can win the first prize in the contest.
| A．There; whether | B．It; whether | C．There; that | D．It; that |
It took a long time for the effective use of natural gas ______.
| A．making | B．being made | C．to make | D．to be made |