Transcription and translation
DNA is transcribed into mRNA using complementary bases, with uracil replacing thymine, and tRNA anticodons then read the codons.
A worked example
A template strand 3'-ACG TTA-5' transcribes to mRNA 5'-UGC AAU-3', which two tRNAs read as two codons and so two amino acids.
The mistake people actually make
RNA never contains thymine, so any answer with a T in it is wrong. Line the mRNA up antiparallel to the template, with 5' against 3'.