胚胎的性别早在受精时就决定了。The sex of the embryo is predetermined at fertilization.收集母牛胚胎的方法有两种, 一种是直接通过产道, 另一种是施用外科手术.There are two methods of collecting cow embryos -- directly through the birth canal, or surgically.目的: 探索制作小鼠多倍体胚...
大人尚且举不起来, 何况小孩子.Even grown - ups can't lift it, to say nothing of children.我们死都不怕, 何况困难?We fear no death, let alone difficulties.你跑得那么快还赶不上他, 何况我 呢 ?If a good runner like you can't catch up with him, how can I?...