He had been a rock in the shifting sands of her existence.他一直是她曲折坎坷的生活中的主心骨。The sands of his life are fast running out.他的寿命很快将尽.Children enjoy playing on the sands.孩子们喜欢在沙滩上玩耍....
He looked physically very powerful, athletic in a compact way.他看上去非常强壮，像个敦实的运动员。Compact discs have brought about a vast improvement in recorded sound quality.激光唱片极大地提高了录音的音质。Photos taken by compact cameras are often dark...
ECHO cloning is a rapid, easy and common DNA recombination technique.目的:利用ECHO克隆 系统建立一种更加快速 、 方便、通用的DNA重组技术.The methods include using Agrobacterium - mediated transformation , electroporation, gene gun bombardment andgly...