It is said that sandstorms will become more as a result of global warming.A. frequentB.

问题补充：

It is said that sandstorms will become more as a result of global warming.

A. frequent

B. normal

C. formal

D. rare

答案：

(答案→)A. frequent

B. normal

C. formal

D. rare

解析：考查形容词; A. frequent频繁的B. normal正常的C. formal正式的D. rare稀有的，句意：据说由于全球气温变暖沙尘暴会更频繁的。选A。