硬脊膜外腔阻滞麻醉时必须注射试验剂量的局麻药,主要是为了预防()
A.麻醉药物过敏
B.麻醉药物中毒
C.麻醉范围过广
D.全脊髓麻醉
E.以上都不是
参考答案:D
The teacher highly recommended that I ___________ more to improve my English.
A.would practice
B.could practice
C.practice
D.practiced
地球上近地层风能总储量约为目前世界能耗的()倍
A.100
B.1000
C.10000
D.100000