Fill in the blanks with the proper forms of given words.

I helped my mother to buy some beef and three (potato) for supper today.

"Belt and Road"（一带一路) are the two wings of developing Asia in the (twenty-one) century.

Please keep (silence) in the concert hall because people are enjoying Lang Lang's piano performance.

Candy  (lay) out the tea, fruit and snacks on the table and waited for the visitors.

.With the development of technology, mobile phones are  (wide) used these days.