dna ** the main constituents of chromosomes, but also genes, sometimes referred to as "hereditary particles". dna ** a molecule made up of genetic instructions, to guide the biological devel...
因为 what ** 是疑问句, which **是选择疑问句。 what ** what, which ** which与who ** who 这三个表达在口语中非常常用,由于其结构相同,用法相似,所以经常被弄混。本文拟对其用法区别作一归纳。 what’s what在口语中通常与动词know, learn, show, tell, perceive等连用,其主要用法有: 1. 表示“哪...