1. very helpful.....me
3.too...to catch up with
4. have been in
too...to...eg. She is too young to go to school.
She is so young that she can't go to school.
She is old enough to go to school.这三句意思都是“她太小不能上学。”第一句为简单句，第二句为复合句so后面加形容词或副词 再接that 引导的从句，第三个句子为简单句，enough 前面要为前面句子的形容词的反义词，也就是前面为young 那么此句要用old.
are able to
has a good sense of humour
1.how many times
likes telling jokes makes us laugh
It's efficient for
so forgetive that
too clever to
1. As a_librarian__,she works to serve readers
2.The more exercise you take ,the _healthier__ you'll be
3 He spent as much time as he could __practicing__ writing in Enlish
4 When I walked into the kitchen,I found the glass was _broken_ on the floor
5 Be carful,or you won't work out the physics problem__successfully__.