It is very kind ____ you to help me with these maths problems because it is very difficult ____ me to work them out.
—How old is Mary?—________.We had a special party for her________birthday yesterday.A.Twenty;twentythB.Twenty;twentiethC.Twenties;twentieth
(安徽)Rick has learned a lot about Chinese culture________he came to China.
Miss Lin________a lot of work for the poor area since 2010.
—________have you been in Chongqing?—For five years.
They dug up the road and________a box hidden under it.