Answer:
1 2 and 3
Step-by-step explanation:
Number one flows smoothly and does not break any grammar rules.
Number two contains a semi-colon, which is used to break up two clauses without a comma or a period. In this sentence, it does just that, flows smoothly, and does not break any grammar rules.
Number three flows smoothly and does not break any grammar rules.
If further explanation is needed, let me know! I hope I've helped :)