连词成句，注意单词的大小写及标点符号。
1. your, what, head, to, happened (?)
__________________________________
2. a, we, watermelon, bought, so (.)
__________________________________
3. watermelon, Sam, the, carried, bikc ,the, on (.)
__________________________________
4. his, then, fell, Sam, bike, off (. )
__________________________________