用pH试纸测定食用白醋的酸碱度.如果先将pH试纸用蒸馏水润湿后,再把白醋滴在pH试纸上,则测得的pH( )
A.偏高
B.偏低
C.相同
D.难于确定
答案:A
—Do you know how I can ____ him?
—On his mobile phone.
A.learn
B.reach
C.seek
D.touch
用显微镜观察小鱼尾鳍内血液的流动时,可以看到______、______和______三种血管.