On April 16th, astronauts Zhai Zhigang, Wang Yaping and Ye Guangfu came back to Earth from the Tiangong space station ________.
widely
especially
highly
safely
What _____ it is to go camping in _____ weather!
---- How does your father usually go to work? ---- He _____drive a car, but now he _____ there to lose weight.
The math problem is _____ difficult that only _____ students can work it out.
________ fathers are both doctors.
Please __________ the light when you leave the classroom.