边材含有木质导管, 但不如中心木质那样坚硬.Sapwood contains xylem vessels, but not as strong as heartwood.毛白杨边材材色株间存在显著差异.Thecolor of sapwood of Chinese white poplar among trees has significant difference.边材色稍浅,仅导管槽带有红色.Sapwood pale colored ...
他避开了最棘手的问题，将精力集中于有可能达成一致的领域。He skirted the hardest issues, concentrating on areas of possible agreement.他和我把这个棘手的问题整个儿都讨论清楚了。He and I have talked through this whole tricky problem.即使不把宗教牵扯进去，这个问题也已经够棘手的了。It's diffic...