1. the author submitted the report on time. ( change into the passive voice)
=> The report was submitted by the author on time.....
2. i am so tired that i can't work any more. ( rewrite using 'too')
=> i am too tired to work...
3. he has been working very hard to clear the entrance examination. ( rewrite as a complex sentence using an advebialclause)
=>He has been working hard as he wanted to clear the entrance examination.
4. the weather is wonderful. ( rewrite as an exclamatory sentence)
=>How wonderful is the wheather!
5. rajni is the tallest of all.( rewrite using the comparative degree)
=>No other girl in class is as tall as rajni....