主动脉弓靠左侧发出的第一个分支是（）。
A.头臂干
B.左颈总动脉
C.左锁骨下动脉
D.右颈总动脉
E.右锁骨下动脉
参考答案：C
为庆祝“六一”儿童节，同学们用彩色小灯泡布置教室，按“3红、2黄、2绿”的顺序连接起来，第37个小灯泡是[ ]
A．绿色
B．黄色
C．红色
用所给单词的适当形式填空。
1. Look, it's ____________ (cloud) now. I think it's going to rain soon.
2. Song Zuying is a ____________ (sing).
3. Are there any interesting ____________ (activity) this evening?
4. He ____________ (not live) in Paris.
5. I like dogs because they are ____________ (friend) to people.
