Read the following article and answer the question. Article: MOST recently, my world has been shaken by the death of a teacher at my school. He was Dr Allan Woolley and he was only 52. Suddenly he took his own life, which remains a mystery. That morning, everyone sensed that something wasn't right. During our lessons, an announcement was made that an assembly was scheduled for morning break, which was only done in emergencies. Once morning break came, the entire school gathered in the main hall. As our headmaster marched out to announce the "momentous news", it felt like the air around us trembled . Many students broke down in tears, and the reaction afterward was intensely powerful and unifying . The headmaster said that students were allowed to miss lessons and have a free period to _ themselves if they found the news too distressing . Many students went outside and shared memories of Dr Woolley to control theirselves. Dr Woolley taught me chemistry two years ago, but up until his death he still taught many of my close friends. Many of my friends were so shocked that they still couldn't believe the person that they had owed some homework to was now dead. It was heart-warming to spend time with teachers that morning and get to know more about them. _ Question: Which of the following is NOT true according to the passage? Answer:

Select from the following.
+The real cause of Dr Woolley's death is known to us.;
+Many students didn't prepare themselves for the bad news so that they felt very sad.;
+It takes the whole school some time to recover from the dispressing news.;
+Dr Woolley's death allows students to understand teachers better.;
Answer:
The real cause of Dr Woolley's death is known to us.