.whose are these?———?A.Yours B.Their C.Is it his D.Your sist

.
whose are these?———?
A.Yours B.Their C.Is it his D.Your sister‘s
This is____opportunity to be lost
A.too good B.an too good C.too a good D.a too good
Fried is ___of Mrs.Ross's two sons.
A.the tallest B.the taller C.tall D.taller
New York and Boston are two of__seaports in the world.
A.the busier B.the busiest C.busier D.busiest
Of my three courses,history requires___reading.
A.more B.the most C.much more D.many