With time changing so fast, to keep _____ with time, anyone should be a lifelong learner, or he will fall behind within years.

Mrs. Smith lives next to us. She is really a good ______ because she is always ready to help people around her.

He was brave enough ___________ for the school volleyball team and succeeded.

When he fell off the bike, he tried ____ but couldn’t .

Xu Beihong is known _____ a great Chinese painter.— Yeah. He is famous _____ his horse paintings.