某有机化合物仅由碳、氢、氧三种元素组成，其相对分子质量小于 165，若已知其中氧的质量分数为 50%，则分子中碳原子数最多为

A．4

B．5

C．6

D．7

What ______ had Bob walked farther, as far as the river bank?

A．would happen

B．could happen

C．would have happened

D．needn’t have happened