8. That's the man whose car I lent
9. No matter how hard I tried, I couldn't get the money
10. However you are an experienced driver, driving fast is dangerous

4. No matter how long you use it, it won't wear out
5. However hard I tried, I ....
6. However long it may take, I'll find that man
7. .... I can't go to the cinema tonight is I don't have a car 
8. .... whom I lent my car to
9. .... how hard I tried as I could, I just ....
10. .... experienced a driver you are, driving fast is dangerous.

1.we were suprised at what he had done
-->what he had done surprised us
2.no matter what you do,don't touch this
-->whatever you do, don't touch this.
3.you can use it as long as you like,and it won't wear out
--->no matter how long you use it, it won't wear out
4.no matter how hard I tried,I couldn't open the door
--->however hard I tried,I couldn't open the door
5.I'll find that man,no matter how long it takes
--->however long it takes, I'll find that man
6.I can't go to the cinema tonight because I don't have a car
-->the reason why I can't go to the cinema is that I don't have a car
7.I lent my car to that man
--->that's the man to whom I lent my car.
8.I tried hard as I could but I just couldn't get the money
-->no matter how hard I tried, I couldn't get the money
9.Driving fast is dangerous whether you are an experienced driver ỏ not
-->however experienced a driver you are, driving fast is dangerous