) ▁at ▁bay ; ▁as ▁between ▁May ▁ 2 3 ▁and ▁June ▁ 3 ▁the ▁troops ▁were ▁ordered ▁not ▁to ▁move ▁on ▁the ▁un ar med ▁students . ▁Once ▁author ized ▁to ▁use ▁force , ▁the ▁P LA ▁broke ▁through ▁student ▁pick ets ▁and ▁entered ▁the ▁square , ▁demonstr ating ▁the ▁in ability ▁of ▁the ▁pick ets ▁to ▁resist ▁the ▁army . ▁ ▁Once ▁the ▁crack down ▁began , ▁the ▁respons ib ilities ▁of ▁the ▁pick ets ▁w iden ed ▁to ▁include ▁maintain ing ▁order ▁during ▁the ▁square ’ s ▁ev acu ation , ▁as ▁well ▁as ▁phys ically ▁protect ing ▁the ▁Def end ▁T ian an men ▁Square ▁Head quarters ▁leaders , ▁which ▁facil itated ▁the ▁escape ▁of ▁Ch ai ▁L ing , ▁F eng ▁Cong de , ▁Li ▁Lu , ▁and ▁Wang ▁Cha oh ua . ▁ ▁Att empt ing ▁to ▁exercise ▁effective ▁authority , ▁the ▁Head quarters ▁established ▁a ▁central ▁location ▁so ▁that ▁they ▁could ▁create ▁security ▁lines ▁and ▁be ▁found ▁easily . ▁It ▁is ▁important ▁to ▁note ▁that ▁the ▁intended ▁use ▁of ▁these ▁security ▁lines ▁diff ers ▁between ▁the ▁English ▁and ▁Mand arin ▁versions ▁of ▁Ch ai ▁L ing ’ s ▁mem oir . ▁Her ▁Mand arin ▁version ▁notes ▁that ▁the ▁lines ▁are ▁intended ▁to ▁protect ▁students , ▁whereas ▁the ▁English ▁version ▁states ▁they ▁are ▁for ▁the ▁protection ▁of ▁the ▁leaders . ▁Consider ing ▁the ▁English ▁version ▁of ▁her ▁mem oir , ▁Ch ai ▁L ing ▁states ▁that ▁phys ically ▁strong ▁students ▁were ▁chosen ▁for ▁security ▁roles , ▁such