他从耳后拿出一小段铅笔头。He pulled the stub of a pencil from behind his ear.铅笔头the stump of a pencil他咬着铅笔头，仔细思考着下一道题。He chewed at the end of his pencil, thinking out the next problem....
Liberty often degenerates into lawlessness.自由常常变质为无法无天.Her health degenerates rapidly.她的健康状况迅速恶化.The human stock goes on, even though it degenerates.虽然衰败了, 但这样的家族还在延续....
在医用直线加速器中通常都采用磁控管作为微波功率源.Magnetron is often used as microwave power source in clinical linac magnetron.本论文重点研究的是嵌入式系统在电子直线加速器 磁控管 频率自动跟踪控制中的应用.The AFC system of LINAC , based on the Embeded - system, is studied in the pa...