根据首字母及句意补全单词
1.You can watch people cilmb on knives ,it's really f_________!
2.The sailfish can swim 109km p_________ hour!That's faster than most boats!Amazzing!
3.The marathon is the longest r_______ at the Olympics.It is 42.195km long.
4.Yang Liwei f________ around the Earth for more than 21 hours in the Shenzhou g.