Mandela ,who devoted all his life to the freedom of South African Blacks and died on December 5th in 2013, is a real fighter for us to_________.
It was______ back home after the experiment.
______ I have made great progress in my spoken English, I can not express myself freely.
It is _____ he often fails in exams _____ makes his parents worried about him.
Waves of red light are about twice as long as _______ of blue light.
Eventually, the husband could no longer ______ his wife’s complaints about his inability to make much money, and he divorced her.