As is so often pointed out,knowledge is a two-edged sword which can be used____for good or evil
His health failing, ______ last year.
As a student in Senior Three, I must work hard. ______, I should take exercise to strengthen my body.
No person __________ carry a mobile phone into the examination room during the national college Entrance Examinations.
_____ about the man wearing sunglasses during night that he was determined to follow him.
I really don’t know how to thank you , but for your help, I ______ my lost necklace.