劳累性心绞痛包括________、_________、________
参考答案：稳定型心绞痛；初发型心绞痛；恶化型心绞痛
The teacher, ____ his book ____ hand, came over to the
blackboard.
A．with; in
B．/; in
C．on; on
D．with; /
皮肤组织起源于：（ ）
A．外胚层
B．中胚层
C．外胚层和中胚层
D．外胚层和内胚层
