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 we remain inveterate smokers, it is only because we have so often experienced the frustration that results from failure.
如果我们烟瘾大,戒不掉,那是因为屡戒屡败,失去信心。