The machine is hard to (控制). There must be something wrong with it.
Professor Xu gave us a talk on how to (保护) the environment last week.
The school will hold many activities to (庆祝) our country's 70th birthday.
Shall we go outside and breathe some (新鲜的) air?
Good ideas.
Liu Cixin is the (作家) who wrote the science fiction novel The three Body Problem.
﹣Dick, is this your T﹣shirt?
﹣Yes, it's (我的). I looked for it everywhere.
This is not the first time for the two teams to play (对抗) each other.
Please put all the books back in the right (顺序) before you leave.
I've had a lone (累人的) day. I need a good rest.
In his (八十), I. M. Pei (贝堇铭) designed Suzhou museum for his hometown.
President Xi Jinping (颁发) the Top Science Award to Liu Yongtan and Qian Qihu for their great contributions to science and technology in January, 2019.