Customs officers at a London airport yesterday found 50，000 poun

Customs officers at a London airport yesterday found 50，000 pounds worth of drugs which were being smuggled (走私) into Britain in boxes marked “Urgent Medical Supplies”.The authorities might have suspected for some time ___26___ drugs would be brought into the country in this way. The operation is believed to be the work of a ___27___ international group. Four men were arrested at ___28___ airport and held for questioning, ___29___it is unlikely that they are the organizers. In ___30___ they declared that they were ___31___ of what the boxes contained and had acted in good faith in bringing ___32___ into Britain. This is the third time ___33___ six months that attempts have been made to smuggle ___34___ goods through Customs by declaring them to __35____ medical supplies. They are frequently ___36___ in special containers and a note is given that they may be damaged if they are not handled with care.“ ___37___ are determined to put a ___38___to this practice，” said one of the Customs officers today. “ __39____ is no way these people are going to get away ___40___ this any longer. We have the full co-operation of the international police to track down the main source of supply.”
回答第33空
A、of
B、for
C、by
D、within
【正确答案】：D
【题目解析】：本题考查介词。空格前是 the third time，表示第三次，空格后是 six months，表示一段时间。再结合选项可知，这里是指 6 个月内第三次。故选 D。