— The classroom is ______ clean ______ it was yesterday.— Sorry, I forgot to clean it.
— Food problem is becoming a big one in China!—I think the food ________ before going to shops or supermarkets.
English _____________ in more and more countries today.
— I didn’t see you at Kangkang’s birthday party.— I didn’t go because I _____ .
Zhengzhou will be more and more convenient when Zhengzhou Subway_____ in two years.
Food safety is important. Rules must ________ stop people from food pollution.