16.　 Learning about the _______________ (性质；特性) of water helps us understand life on our planet.

15.　 One cubic meter of water weighs one thousand __________________ (千克；公斤).

14.　 When _____________ (溶解) gases and solids mix with pure water, the result is sea water.

13.　 When water freezes, its density ____________ (减少；变小).

12.　 The ____________ (含盐量) of the earth’s oceans is about thirty- five parts per thousand.

11.　 Most animals and plants are _____________ (敏感的；灵敏的) to large or sudden changes in temperature.

10.　 The water in the oceans also keeps the temperature of the earth steady by ____________ (吸收) and giving off heat.

9.　　　 Life in the oceans appears in different sizes, ____________ (变化；变动) from the tiniest fish all the way up to the biggest blue whales.

8.　　　 Marine scientists study the ______________ (关系；联系) between living creatures and their habitat in the ocean.

7.　　　 Oil has a density lower than 1,000 kg/m⒊, so it will ___________ (漂浮) on water.