With a shortage of chromosomes, a developing fetus will likely grow into a child with down syndrome.
如果缺省染色体,一个处于成长阶段的胚胎可能发育成一个具有不良综合症的小孩。
If they knew how difficult it was to drill through the hard rock, they would lose heart.
如果他们知道了钻透那坚硬的岩石有多么困难,他们会丧失信心的。