Which of the following variations in magnetic declination are correctly paired with their respective causes? 1) Diurnal variation - Temperature variation may cause this type of variation2) Secular variation - Earthquakes may cause this type of variation3) Irregular variation - Magnetic storms may cause this type of variation

In survey work using a total station with reflector measurements, which of the following sequence of temporary adjustments must be performed at a station?

While carrying out a total station survey on one bank of a 250 m wide river, it is necessary to plot electric transmission posts on the opposite bank. No provision exists for crossing the river and the posts are inaccessible. In which mode should the survey work be done?