强调句
It is/was … that/who/whom… 强调除谓语以外的任何成份
1 It was my sister who first had the idea to cycle along the Mekong River from where it begins to where it ends.(p18 para1)
2 …it’s because I haven’t been able to be outdoors for so long that I’ve grown so crazy about everything to do with nature.P.2