They eat less sugar and that’s they have white teeth.A. because healthyB. why healthC.

问题补充：

They eat less sugar and that’s they have white teeth.

A. because, healthy

B. why, health

C. because, health

D. why, healthy

答案：

A. because, healthy

B. why, health

C. because, health

(答案→)D. why, healthy

解析：考查连词及形容词。Why引导的从句内容表示的是结果，because引导的从句表示原因。healthy修饰名词teeth。句意：他们很少吃糖，那就是他们为什么有健康洁白的牙齿的原因。