与新斯的明比较,毒扁豆碱的药理作用显著特点是
A.对心血管系统作用较强
B.对骨骼肌兴奋作用更强
C.对胃肠平滑肌作用较弱
D.具有中枢作用
E.对腺体分泌作用较弱
参考答案:D
_____ is very useful for us students _____ English well. [ ]
A. This, to learn
B. That, to learn
C. It, to learn
D. It, learns