?? ?????????? ???????? ?????
??? ??????
(
???????????
:
Service ceiling
)? ??
???? ??????
???????
?? ???? ?????? ???
????? ??? ?????
???? ????
??????
????? ?? ???? ????? ????? ???? ??? ??? ???? ??? ???? ?????? ???? ?? 100 ??? ?? ??????? ??????? ?? ?? ???? ???? ??????.
[1]
???? ????
[
???
]
?????
[
???
]