题目

Yesterday we learned some new words and now       .   A. think them about                               B. think over them   C. think them over                                        D. think it over 答案：C图描绘了少年沃尔特·霍利（16世纪英国著名航海家）与经验丰富的老船员交谈的情景，他们谈论的论题不可能涉及（   ）A．哥伦布的海洋冒险B．大豆、玉米的引种C．非洲黑奴的贩卖D．蒸汽轮船的航行