下列哪种药物的中间代谢产物能透过血－脑脊液屏障并产生麻醉作用（）
A.依托咪酯
B.硫喷妥钠
C.芬太尼
D.羟丁酸钠
E.丙泊酚
参考答案：D
中国加入世界贸易组织（WTO）有何积极意义？
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There were already four people in the lift, but he managed to in. [ ]
A. slide
B. squeeze
C. sweep
D. push
