英语专八人文知识汇总 美国概况 练习题： 1 The traditional dividing line in America between “east” and “west” is_____. 2 The earliest part in America to be found and taken over by early settlers is ____. 3 The largest racial group in the whole population of U.S.A is___
1. be absent from…. 缺席，不在 2. absence of mind(=being absent-minded) 心不在焉 3. absorb(=take up the attention of)吸引…的注意力(被动语态):be absorbed in 全神贯注于…近:be engrossed in ; be lost in ; be rapt in ;be concentrated on ; be focused on ; be centered on 4. (be) a
立创商城 “双11”--- 商品推荐总汇-5032-4P-8MHZ.pdf雅晶鑫
● SUGGESTED REFLOW PROFILE(回流焊曲线图)
Total time:200 sec. Max.(总时间:200秒最大)
Solder melting point:220℃(熔点220℃)
Profiles feature(特性)
Pb-Free assembly
Average Ramp- up rate( Ts max to Tp)平均升温速度
3℃C/ second max
Prehea
