The blacks who received Nobel Prizes for Literature are: a. Toni Morrison and Dereck Walcott. b. Toni Morrison, John Steinbeck and Wole Soyinka. c. Toni Morrison, Dereck Walcott and Wole Soyinka. d. Toni Morrison, Dereck Walcott and John Steinbeck.

患者术前血压170/100mmHg，心率84次/分，在异氟烷吸入麻醉下胃癌根治术。诱导后当异氟烷浓度达1.6MAC时。血压降至95/50mmHg，心率为118次/分，ECG出现多个室性早搏。

此时低血压最可能的原因是()

A．血容量过低，回心血量少

B．麻醉药物选择不当

C．病人出现急性心力衰竭

D．吸入麻醉过深，心血管受抑制

E．术中发生脑血管意外