英语的(括号里的词改变时态)

I can't avoid _______(meet) the manager because I have something important.
_________(serve) the people all through one's life is not easy.
When to start for Beijing on holiday ________(not decide) yet.
Please remember ______(give) my best regards to your parents when you are back home.
She is not what she used _______(be)
Hongkong's return is a great event thar _____(touch)on many people's life.
Before _____(learn) the text ,you'd better learn something about the backgrand of stary.
注：最好能够帮我附上理由，谢谢:-)

I can't avoid _meeting_(meet) the manager because I have something important.
avoid doing sth.
_Serving_(serve) the people all through one's life is not easy.
因为后面后谓语is，所以用动名词serving
When to start for Beijing on holiday __has not been decided__(not decide) yet.
因为后面有yet，用于现在完成时的否定句，并且这个时间的决定是被动
Please remember _to give____(give) my best regards to your parents when you are back home.
remember to do 解释为记得去做某事 补充：remember doing 是记得做过某事
She is not what she used _to be _____(be)
used to be 是固定词组 解释为 过去曾经是/常常是
Hongkong's return is a great event thar（应该是that吧） __touches___(touch)on many people's life.
这是一句定语从句，从句部分 touch on many people's life 是用来修饰event的 因为是单数，所以用三单形式
Before _learning____(learn) the text ,you'd better learn something about the backgrand of stary.
before是介词，介词后面跟名词或动名词，这里用动名词learning

meeting; avoid后面跟名词或动名词。

Serving; is前面的是主语，要用动名词形式。