v.
1) ( D ; intr. ) to ~ in (she has ~d in English)
2) ( d ; intr. ) to ~ on, upon (I cannot ~ on her performance)
IMPROVE
Meaning of IMPROVE in English
The Bbi combinatory dictionary of English, a guide to word combinations. Комбинаторный словарь английского языка Bbi. Руководство по словосочетаниям. 2012