Analysts have their go at humor, and I have read some of this interpretative literature, （

Analysts have their go at humor, and I have read some of this interpretative literature, (1)_____ without being greatly instructed. Humor can be (2)_____, (3)_____ a frog can, but the thing dies in the process and the innards are (4)_____ to any but the pure scientific mind.

One of the things (5)_____ said about humorists is that they are really very sad people clowns with a breaking heart. There is some truth in it, but it is badly (6)_____. It would be more (7)_____, I think, to say that there is a deep vein of melancholy running through everyone's life and that the humorist, perhaps more (8)_____ of it than some others, compensates for it actively and (9)_____ Humorists fatten on troubles. They have always made trouble (10)_____ They struggle along with a good will and endure pain (11)_____, knowing how well it will (12)_____ them in the sweet by and by. You find them wrestling with foreign languages, fighting folding ironing hoards and swollen drainpipes, suffering the terrible (13)_____ of tight boots. They pour out their sorrows profitably, in a (14)_____ of what is not quite fiction nor quite fact either. Beneath the sparking surface of these dilemmas flows the strong (15)_____ of human woe.

Practically everyone is a manic depressive of sorts, with his up moments and his down moments, and you certainly don't have to be a humorist to (16)_____ the sadness of situation and mood. But there is often a rather fine line between laughing and crying, and if a humorous piece of writing brings a person to the point (17)_____ his emotional responses are untrustworthy and seem likely to break over into the opposite realm, it is (18)_____ humor, like poetry, has an extra content, it plays (19)_____ to the big hot fire which is Truth, and sometimes the reader feels the (20)_____.

A．while

B．although

C．but

D．if