例：I’m tall.Your brother is short.→ I‘m taller than your brother.例：I’m tall.Your brother is short.→ I‘m taller than your brother.1.She's 11 years old.I'm 13 years old.→2.Mike is 50 kg.He's 160 cm tall.Sarah is 45 kg.She's 160 cm tall.→3.My mother is short.My father is tall.→

1. She is younger than me.  or I am older than her.

2. Mike  is heavier than Sarah, and as tall as Sarah.
   

3. My mother is shorter than My father.
   

为你解答。
1、She's 11 years old. I'm 13 years old.
→ She is younger than I.
2、Mike is 50 kg. He's 160 cm tall. Sarah is 45 kg. She's 160 cm tall.
→ Mike （is as tall as Sarah, but he） is heavier than Sarah.
解释：括号部分由你决定是否要写。
3、My mother is short. My father is tall.
→ My mother is shorter than my father.

I'm older than her.
Mike is heavier than Sarah, and as tall as Sarah.
My mother is shorter than my father