Watching The Legend of Luo Xiaohei is a good ________ to relax when you're tired．（ ）
A．ruleB．choiceC．questionD．skill
Artemisinin _______ by Tu Youyou，a great Chinese scientist．（ ）
A．was inventedB．invented
C．has invented
As our children get bigger，our house seems to get ________．（ ）
A．the smallerB．smaller
C．smallest
The watch _______ you gave me keeps perfect time．（ ）
A．whoB．whatC．that
She went to a European university to study art．_______ university is really amazing．（ ）
A．AnB．TheC．A
He ________ in Zhuzhou since seven years ago．（ ）
A．worksB．workedC．has worked