如图所示，用导线把电池、小灯泡和一段粗细均匀的电阻丝连起来。当金属夹从电阻丝上的某点沿电阻丝向               移动的过程中，小灯泡亮度逐渐变暗。这表明导体电阻的大小跟导体的              有关。

根据母及句意补全单词。

1.  He is very t          , and he drinks a lot of water.

2.  Take this m     three times a day and you'll feel better.

3.  I have to see a d        because of my toothache.

4.  I'm often s       out when we have tests.

5.  It is very important for us to eat a b        diet.