A:在高倍镜下观察可以看到叶绿体具有基粒
B:活细胞细胞质基质中的叶绿体是静止不动的
C:选用含叶绿体大而少的细胞来观察
D:制片时叶片应保持干燥
100以内的偶数和是____ .
He was a ____(代表) of Russia to the UN.
The TV is too loud. Could you please ________?