(2018沈阳)My grandparents wrote letters to keep in touch with others ________ they were young.
A.when B.since C.after D.before
(2018扬州)Hawking is no longer with us, ________ he will continue to inspire the world.
A.so B.if C.but D.as
(2019原创)Everyone should wait in line outside. You couldn't come in u________ your name is called.
(2019原创)T________ he is only seven years old, he knows a lot about science.
(2019原创)I'm sorry. I forgot to take out the rubbish w________ I left home in the morning.
(2019原创)My mom always cooks chicken soup for me b________ it's good for my health.
