—What should we do for the disabled children in the Children's Home?
—You're supposed to________ a study group to help them.
A:take up
B:fix up
C:set up
D:stay up
A.1s22s22p63s23p63d54s2 B.1s22s22p63s2
C.1s22s22p6 D.1s22s22p63s23p2 E.Ar4s1。
请用元素符号回答下列问题:
下列各数中,最小的实数是()