题目

It is not a good idea for children to have to work hard. Children should study in school as hard as they can. They should not have to do heavy work with their bodies. When parents or others force(强迫)their children to work hard, the results are never good. Many may be very bad. If a farmer makes his son work like a man, he may easily learn to hate farming.       Children sometimes do too much in gardens, in shops, or even in their own homes. They soon begin to hate such work with a force, because that can destroy their happiness. But there may be a worse loss, child’s love for its p（2012•钟祥市模拟）已知底面是正三角形，顶点在底面的射影是底面三角形的中心的三棱锥V-ABC的主视图、俯视图如图所示，其中VA=4，AC=23，D为棱CB的中点，则该三棱锥的左视图的面积为（　　）A．9B．6C．33D．39