已知数列$\left\{a_n\right\}$中，$a_1=1$前n项和为S_n，且点$P\left(a_n,a_{n+1}\right)\left(n\in N^{*}\right)$在一次函数y=x+1 的图象上，则$\frac{1}{S_1}+\frac{1}{S_2}+\frac{1}{S_3}+...+\frac{1}{S_n}=$（   ）

提示词：listen to, mother's love, care about, communicate with, get along with, smile

要求：60~80词，可适当发挥。

Dear Wang Ning,

    I'm afraid I've got a big problem recently. My mother talks too much to me. She always tells me,“Be careful while crossing the street.”“Put on more clothes.”“Did you do a good job at school?”and so on. I'm annoyed（烦恼的）.What shall I do?

Yours,

Tina