甲：将一个正在响的响铃放在玻璃钟罩内，然后将钟罩内的空气抽去一些，铃声明显减小；

乙：使正在发声的音叉接触水面，水面激起水花；

丙：在鼓面放一些小纸屑，击鼓时纸屑随着鼓一起跳动；

丁：吹笛子时，手指按住不同的孔便会发出不同的声音；

上述现象中能够说明声音的产生条件的实验现象是____和____；其中甲同学的现象说明了声音____；丁同学的现象说明了声音有不同的____．

根据句意及首字母提示填空。
(1)You can ask a____ around you for help when you are in trouble.
(2)The girl will give us a c____ in English this afternoon.
(3)His s____  cheered the girl up. She was very thankful (感谢的).
(4)She always feels n____  when she speaks in public.
(5) —Don't make so much n____ . Your father is sleeping. —Sorry, Mom. I won't do that again.