题目

  （7）------中偏难题 People generally use spices （香料） every day when preparing meals．Most of these spices are readily available in local supermarkets．However, in the 15th and 16th centuries, spices were as valuable as gold or diamonds．Spices are small plants or parts of plants, such as ginger, pepper, vanilla, and cinnamon, which are used to add flavor to our food． 1   Such a use for spices actually goes all the way back to Roman times．The Romans used spices such as cumin and coriander to help preserve food．     The spices came to Europe from countries to the e有一种波，其波形为函数的图象，若其区间[0,t]上至少有2个波峰（图象的最高点），则正整数t的最小值是                                       A．5                            B．6                            C．7                            D．8