A recent evening stroll through our downtown was a perfect showcase of the warmth l've come to love in China. We experienced a series of unasked-for kindnesses: a genuine compliment for our dog from a stranger, a free tanghulu from a beaming vendor, and even a dinner invitation from a local hotpot owner. It's this environment of spontaneous generosity that makes me feel so at ease with my children's safety. The difference is profound compared to the underlying vigilance I often feel in the UK. T

SN1 and SN2 reaction mechanisms|| Nucleophilic substitution reaction||mechanisms of Sn1 and Sn2||

Nucleophilic substitution