Bob has got good exam results. His parents are proud of his ______.
A:success
B:chance
C:idea
D:dream
已知如图,某学生想利用标杆测量一棵大树的高度,如果标杆EC的高为 1.6m,并测得BC=2.2m,CA=0.8m,那么树DB的高度是( )
____
下列符号中,只具有微观意义的是 ( )
向盛有稀硫酸的小烧杯中慢慢滴加Ba(OH)2溶液至过量,有关量的变化情况见图.其中错误的是( )