019.how long has it been since

019.how long has it been since….自从… 多长时间了？

How long has it been since you had a cold
你感冒多久了？

How long has it been since you began this project
你做这个项目多久了

How long has it been since he moved to Canada
自从他搬到加拿大多久

How long has it been since you graduated from college
你大学毕业多久了？

How long has it been since you gave up your work
自从你辞职后有多久了？