主动脉弓凸侧自右向左发出哪3条动脉？
参考答案：
分别发出头臂干、左颈总动脉、左锁骨下动脉。
The fact has worried many scientists _____ the earth is becoming warmer and warmer these years. [ ]
A. what
B. which
C. that
D. though
什么是信号识别颗粒？
