You should keep some distance between us, and there are many lines you cannot cross (over)!!<br/><br/>There are many lines you cannot <b>cross</b> / <b>cross</b> <b>over</b>. Can I use "<b>over</b>" here without any difference in meaning?<br/><br/>And the whole sentence is natural to you?<br/><br/>Thank you so much as usual and I hope to hear from you.