1, There has been a slight drop in the number of people using public transport (slightly) \(\rightarrow\) ...................................................... 2, Revising for exams takes up all my time at the moment (busy) \(\rightarrow\) ...................................................... 3, There was an increased demand for travel , sothe government decided to invest in building the very first metro systems (as) \(\rightarrow\) .......................................................... 4, I don't know much about historical events , so I can't help her with her history homework (if) \(\rightarrow\) .............................................................

1, There has been a slight drop in the number of people using public transport (slightly)

→ The number of people using public transport has dropped slightly

2, Revising for exams takes up all my time at the moment (busy)

→ I'm busy revising for exams at the moment

3, There was an increased demand for travel , sothe government decided to invest in building the very first metro systems (as)

→ The government decided to invest in building the very first metro systems as there was an increased demand for travel

4, I don't know much about historical events , so I can't help her with her history homework (if)

→ If I knew about historical events, I could help her with her history homework