TASK DEFINITION: Translate the given Spanish text to English
PROBLEM: A threaded joint is constituted by a pin (10) and a box (20).

SOLUTION: Una junta roscada está construida con un perno (10) y una caja (20).

PROBLEM: A mobile system (4).

SOLUTION: Un sistema móvil (4).

PROBLEM: -D-thio-LNA, ???

SOLUTION:
?-D-tio-LNA, ?