护士指导梗阻性肥厚型心肌病患者避免屏气的主要目的是()
A、避免心衰
B、避免出血
C、防止晕厥
D、防止栓塞
E、防止抽搐
参考答案:C
Mr. Hall understands that _______ math has always been easy for him, it is not easy for the students.
A.unless
B.since
C.although
D.when
打开右转向灯开关,(如图所示)亮起。