A:150种
B:1200种
C:9720种
D:18000种
通常情况下,分子式C63H103O45N17S2的多肽化合物中最多含有多少肽键( )
He fell off the bike and hurt his leg yesterday._______, he had to stay at home for two or three months.
根据不同的环境运用诗句。
一天,我和妈妈一起去看瀑布。当我看到长长的瀑布从山顶飞快地直泻下来,那么壮观,我不由得想起一句诗:“ ____,____ 。”