Birds singing is sometimes a warning to other birds away.
#88619
A
Stay
B
staying
C
stayed
D
to stay
推荐题目
While building a tunnel through the mountains, ______.
#93626
A
an underground lake was discovered
B
there was an underground lake discovered
C
a lake was discovered underground
D
the workers discovered an underground lake
______ when to leave, I could only stay at home, _____ nothing.
#97220
A
Knowing not; done
B
Not knowing; doing
C
Having not known; done
D
Not having known; doing
—What made you so____ ____？—John's not listening to my advice.
#95210
A
annoy
B
annoying
C
to annoy
D
annoyed
Visitors to the hills are greeted by signs them to look out.
#89693
A
warn
B
to warn
C
warning
D
warned