6.Through the odds were greatly against them the brave defenders of the fort waged a (valiant scant) battle against the enemy's troops

valiant

7.Because her condition was so poor after the operation she was placed in the hospital's (Stealthy intensive) care unit
intensive

8.The future is indeed (incalculable strapping) but we must face it with faith and confidence
incalculable

9.After straining and sweating in the hot sun for an hour we realized that we had pushed the stalled care only a(n) (scant intensive) quarter mile
scant

10.Since presently means both right now and in the future any statement containing it must be considered (strident ambiguous)
ambiguous

11.When we made our appeal for funds their response was so (incalculable frigid) that we realized we would have to find other ways of raising money
incalculable

I believe 11 is wrong.

12.Although our club is run more or less democratically we don't have the time to (confer abduct) about every minor detail

confer

13.Creeping (stealthily ambiguously) through the underbush the enemy came within a few yards of the stockade before the guards saw them
stealthily

14.When their pitcher committed the (balk earmark) the umpire advanced our runner from first to second base
balk

15.When a country has been overrun by a conquering army the only way people may have to strike back is by acts of (ambiguity sabotage)
sabotage

All are right.

And I learned a new meaning for balk. :-)

16.Before landing on the shore of New England the first Pilgrim settlers signed an agreement called the Mayflower (Compact Maneuver)

compact

17.Why is that bug (strapping frigid) fellow in the ad always kicking sand into the face of the 98 pound weakling
strapping

18.In her floor exercise the champion gymnast performed some of the most amazing (earmarks maneuvers) I have ever seen
maneuvers

19.We have worked out a good plan on paper now we must decide how we are going to (implement balk it)
implement

20.When he says that his analysis of the problem is (indisputable valiant) all he means is that hes not willing to listen to anyone else's ideas
indisputable

All are right. :-)

thank you

You're welcome.