Louisa Lim: The AIDS activist, Hu Jia, hasn't been seen since Saturday morning, when he was taken away for questioning by police. His family say he sent text messages to friends telling them he'd been detained. In an article written last month, he said the government should acknowledge that its killing of unarmed civilians in 1989 was a serious mistake. "That great weight on our hearts must be lifted", he wrote, "and justice must return". He laid out his plans to stage a vigil in Tiananmen Square on the night of June the 3rd to remember those who died. His detention comes a week after three female activists, who lost relatives in 1989, were held in custody for five days. It's a sign the authorities are moving early to head off trouble ahead of this sensitive anniversary. VOCABULARY to detain - zadržet to hold in custody - držet ve vazbě to acknowledge - přiznat, uznat, ocenit a huge success - obrovský úspěch to stage - zinscenovat, uspořádat to head something off - zabránit něčemu nepříjemnému (nepokoji)