The air in Beijing is much worse than ____________ in many other cities.
A. this B. those C. that D. these
When you ___________ yourself with others, you miss the wonder of who you are.
A. compare B. communicate C. contact D. connect
He decided to study hard_____________ catch up with others.
A. as a result B. so that
C. in order that D. in order to
_______of them can work out the problem, so I have to turn to a third person for help.
A. None B. Either C. Both D. Neither
The robot needs ____________once a month. And we will check it for you for free.
A. to check B. be checked
C. checking D. check
The rocket will travel to Mars _________ a speed of over 25,000 miles per hour.
A. at B. by C. with D. for