--- bad weather yesterday!
---Yes. It caused a few traffic accidents.
A. What
B. What a
C. How
D. How a
网友回答
(答案→)A. What
B. What a
C. How
D. How a
解析：考察感叹句。 weather天气为不可数名词排除BD 根据感叹句句型1，How +形容词+ a +名词+ 陈述语序 2，How+形容词或副词+ 陈述语序 3，What +名词+ 陈述语序 4，What+a+形容词+名词+ 陈述语序 5，What+ 形容词+复数名词+ 陈述语序 6，What+ 形容词+不可数名词+ 陈述语序 排除C 故选A