下列画线字的注音完全正确的一项是（    ）

    I used to go ____ with my mum on clear nights and look at the sky. It looked like black velvet with a million ____ on it. In different seasons, we saw different groups of stars. Sometimes we saw stars ____ brightly ____ the sky. How beautiful they were!

    Studying the stars was great ____ for me. Once I learnt a little about them, I soon wanted to find out more and more. Now it is my ____. I host a TV program ____ The Sky at Night. I use my knowledge to tell people about the stars in a ____ way. I am proud of my TV program me—it has ____ for more than 50 years!

与植物顶端优势有关的植物激素是（　　）