扩张型心肌病第一阶段的临床表现为
A.无症状,X线检查可有心脏轻度增大
B.极度疲劳、乏力症状
C.气促、心悸等症状
D.肝脏肿大,水肿
E.腹水等充血性心力衰竭表现
参考答案:A
Most people think that English is ___________ useful language, but some students think it’s ___________ unimportant subject.
A.a, an
B.a, a
C.an, an
D.an, a
备用凝结水泵的出口电动门应处于关闭状态。