[答案]
Pleaseturnleftatthepostoffice.
[解析]
结合标点和turn可知,句子为祈使句肯定形式。please请,可位于句子之前,后跟动词原形,turn转弯,为动词原形,turn left左转,为动词短语;at the post office在邮局,为介词短语。可组成句子:Please turn left at the post office.
故答案为:Please turn left at the post office.
[点评]
本题考查了"祈使句肯定形式,",属于"基础题",熟悉题型是解题的关键。