期货市场为生产经营者提供了规避、转移或分散( )的良好途径。
A．信用风险
B．经营风险
C．价格风险
D．投资风险
参考答案：C
Along with the letter was his promise _______ he would visit me this coming Christmas. [ ]
A. which
B. that
C. what
D. whether
生物能向前进化的内因是[ ]
A．环境迫使生物产生适应性变异
B．环境对变异进行定向选择
C．生物能努力适应环境的变化
D．生物不断产生不定向的可遗传变异
