父母来了半年不到的时候去申请延期,网上通知体检,正在犹豫,延期签证寄来了,但下面有一行:must undergo immigration medical within 30days. forms have been sent separately. 真不想去体检,也没延多少时间,延了4个月。但不去体检,又不清楚会发生什么。