计算:a5·a2的结果正确的是 [ ]
A.a7
B.a10
C.a25
D.2a7
答案:A
—When did you get to know Sue?
—______ Sep. 1st, 2005. [ ]
A. At
B. In
C. On
D. For
下列神经中,属于肾上腺素能纤维的是
A.支配肾上腺髓质的神经
B.骨骼肌交感舒血管神经
C.交感缩血管神经
D.骨骼肌运动神经