板栗为深根性果树。
参考答案:对
—You haven't been to Beijing, have you — ______. And how I wish to go there again!
A. Yes, I haveB. Yes, I haven'tC. No, I haveD. No, I haven't
功率半导体器件的过压保护主要是针对操作过电压和浪涌电压进行的。