unless,if,after,as if,so that,because,since,while,befor,so..that...答:您好,很高兴为您解答:so that 以使 until "not...until" 直到...才 When 当...时 Although 虽然 Since 既然 unless 除非 so, that 如此...以致 as, as 与...一样 as if 就像 as soon as 一...就...Because 因为 If 如果 while 当..时 before 在...之前 After 在...之后 ...