单项选择题 Section A Directions: There are 10 incomplete statements herYou are required to complete each statement by choosing the appropriate answer from the 4 choices marked A), B), C) and D). You should mark the corresponding letter on the Answer Sheet with a single line through the center. What are the essential differences ___________ selling and marketing?

单项选择题 科技的进步极大的改变了我们的日常生活。今天我们可以①乘坐火车外出旅游，②通过电脑上网查阅资料，③用电话与同学联系，④收看卫星传送的电视节目。其中得益于第三次科技革命的是()

单项选择题 蜡样芽孢杆菌中毒菌量的范围一般在（）