( There ( ( are ( ( ( at least ) two ) ( practical solutions ) ) ) . ) )
(ROOT (S (NP (EX There)) (VP (VBP are) (NP (QP (IN at) (JJS least) (CD two)) (JJ practical) (NNS solutions))) (. .)))
There are at least two practical solutions.
(ROOT (S (NP (DT All) (NNS solutions)) (VP (VBP contain) (NP (QP (IN at) (JJS least) (CD two)) (NNS substances))) (. .)))