reticent
adj
~ (about/on sth) not revealing one's thoughts or feelings easily; reserved 不轻易暴露思想或感情的; 有保留的
be reticent about one's plans 不愿谈自己的计画
He seemed unduly reticent on the subject of his past. 他似乎对他过去的事情讳莫如深.
He who has not tasted bitter knows not what sweet is.
不吃苦中苦,哪知甜中甜。
I'm afraid I can't agree with you. That's a good way of giving information, but it's not a good way of persuading people. For one thing, it's boring, and people aren't going to read an ad that looks boring. For another thing, one computer looks very like