Lucy，could you help me ______ the heavy box to my room—-Sure, a piece of cake.

The book was written ______ careful observations and detailed studies

He has many hobbies, ______ drawing, swimming and so on.

I’m sorry .I can’t play baseball with you. —–________.

I guess you can buy such a smart phone for 300 dollars—I could just two months ago，but the price ________ by 20%