单选题 Whenever he comes across a serious problem, he likes to ______ it, namely, to think it about carefully and for a long time.
【正确答案】 D
【答案解析】[解析] 本题说“当他碰到严重的问题时，他就爱思考”，也就是说，进行长期和仔细的考虑。D项contemplate“仔细的考虑，凝视，注视”符合题意。