A bilingual postal reminder letter was subsequently sent [see Table 2 for dates] to those who had not yet completed the survey, explaining that the deadline had been extended.
Yna, anfonwyd llythyr atgoffa dwyieithog [gweler Tabl 2 am ddyddiadau] at y rhai nad oeddent wedi cwblhau’r arolwg eto, gan esbonio bod y dyddiad cau wedi’i ymestyn.