男性，患冠心病10年，半月来频繁发作心前区不适，含服硝酸甘油无效，疑为急性心肌梗死，最具诊断意义的检查是

A．血常规
B．尿常规
C．血沉
D．超声
E．心电图

linux系统中，以下显示结果相同的是（）。

A、echo The current working path is $PWD.

B、echo "The current working path is $PWD." Echo hello

C、echo 'The current working path is $PWD.' Echo hello

D、echo "The current working path is `pwd`."

E、echo The current working path is $PWD. Echo hello