1, Finish your homework or you can't go out with your friend (if) \(\rightarrow\) .............................................................. 2, They're not sure how they should operate the new system (to) \(\rightarrow\) ............................................................... 3, It took me 4 hours to read the first chapter of the book (spent) \(\rightarrow\) ................................................................ 4, Snowboarding is more dangerous than tennis ( as ) \(\rightarrow\) ....................................................................

1, Finish your homework or you can't go out with your friend (if)

→→.........If you don't Finish your homework , you can't go out with your friend ..............

2, They're not sure how they should operate the new system (to)

→→........They're not sure how to operate the new system................

3, It took me 4 hours to read the first chapter of the book (spent)

→→.........I spent 4 hours reading the first chapter of the book............

4, Snowboarding is more dangerous than tennis ( as )

→→.............Tennis isn't as dangerous as Snowboarding .....................