We haven't met each other ... last year. We still keep ... touch with each other

1/ prepositions;
a/ we haven't met each other...............last year 
b/ we still keep ....................touch with each other 
c/ mrs yen was very surprised .............................the news
2/passive voice;
a/the teacher is going to tell a story
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b/ they cannot solve this problem
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c/ they will hold the meeting before May Day 
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d/ tam has read this book since 5 o'clock
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