By now, more than 100 photos ________ back to the earth by Chang’e-3

for 6 andI’ll at 5 in my car

Do you know sound travels very fast　一Yes. But light travels _________ sound.

______ has recently been done to provide more buses for the people, a shortage of public vehicles remains a serious problem.

. If the water hadn’t been drained out of the mine, no miners _______ alive now.