Nowadays millions of people of all age take pleasure in a               1. _______

hobby which is both interested and fun. And every year                            2. _______

more and more people start a stamp collection of your own                   3. _______

and discover an interest which can even last lifetime. Starting               4. _______

your collection of stamps are easy became they are everywhere.         5. _______

Holiday and birthday postcards from relatives and letters                       6. _______

from friends can all provide you for stamps from all over                        7. _______

the world. So once you’ve started collecting seriously, you                      8. _______

will probably want to join in the Stamp Collectors’ Club                           9. _______

which exist to add more stamps to your collection.                                    10. _______

一艘船的排水量为8000吨，则满载时它受到的浮力为 _________ N，若其最大载货量为5000吨，而现在实际上只载货4000吨，则受到浮力为_________N．（g=10N/kg）