49.It is important for a child to share toys in order to _good social skills .
A. release B.invent C.develop D.start
50. When you get upset, you should take deep breaths to main a sense of _.
A. calm B. humorC. duty D. security
51. Emily Dickinson did not become popular _ her death, when much of her writing was discovered.
A. until
B. soon after
C. shortly before
D. up till