5.Yes,both my best friend Tom and I have!When we were taking part in water sports a few days ago,Tom fidged suddenly and was drawning.At that moment,I struggled to save him with all my strength.It took me quite a few minutes to help him out of water!We were both tired out,lying on the river bank.
6.People may get jerkiness without proper warming up exercise.And if you are sweating,entering cold water to swim directly is also very dangerous.It is a common sense one needs to pay attention to.Good luck!