问题详情：
—Do you often go fishing at weekends?
—Not often，I only go fishing ________.
A．at one time B．all the time
C．at a time D．from time to time
【回答】
D 考查介词短语。at one time“曾经”；all the time“始终”；at a time“每次”；from time to time“有时”。由句意可知D项正确。
知识点：交际用语
题型：选择题
