It was said ( )was how the Chinese first raised silkworms

it is said that that was how the chinese first raised silk w it is said that that was the beginning of raising silkworms it was said ( )was how the fire broke out. It is said that Beijing University was the first The expert insisted that silkworms were first raised by a wo The day,i said ''i like you'',it was the first time,also the It was during the first week of the summer vacation.Dad said How was the food?It was a________________ it was about 20000years ago that the Chinese first made pape It was the first _______(机会,资格)for our Chinese team to take it was the first day of school It was the first time that I ----- ------ ----- ----- ------