Question

across the central andes, long - term ice cores from the quelccaya ice cap ___ a continuous climate record extending back more than 1,500 years. extracted layers preserve annual snowfall patterns, and isotopic ratios are analyzed to reconstruct temperature variation. since the 2016 byrd polar climate archive update, these records have been used to calibrate regional precipitation models. 19 mark for review which choice completes the text so that it conforms to the conventions of standard english? a reveals b reveal c has revealed d is revealing

Explanation:

To solve this, we analyze subject - verb agreement. The subject is "long - term ice cores" (plural). Option A ("reveals") is for singular subjects. Option C ("has revealed") is singular (present perfect) and doesn't match the plural subject. Option D ("is revealing") is singular (present continuous) and also doesn't match. Option B ("reveal") is plural and present simple, which fits the plural subject "ice cores" and the context of stating a general fact about what the ice cores do.

Answer:

B. reveal