We had much difficulty __________ home in the snowstorm.
These beautiful photos _______ on the Great Wall last week.
Do you believe everything _______ is in his book?—No, not really. I only believe something ______ he says.
On April 12, 1961,_____27—year—old Yuri Gagarin(尤里.加加林)became the first human to go into_____ space.
It’snever_______. [ ]