tests by here4u with the online test builder (683 tests)

581. Should ( Ought to) (9532 candidates)
582. Never ... Ever (1965 candidates)
583. Still /yet/ not ... yet (4709 candidates)
584. As/ However /No matter + adjective (12001 candidates)
585. Rescue .... or Revenge 2/2 (1062 candidates)
586. Rescue ....... 1/2 (1366 candidates)
587. To mind and expressions (5196 candidates)
588. Learn and remember (4076 candidates)
589. Other / (the) others ... (2487 candidates)
590. To feel, look, seem, sound ... (6571 candidates)
591. Dozen, Hundred , Thousand, etc. (6697 candidates)
592. All or Whole .... (9363 candidates)
593. The more ... the fewer ... (18135 candidates)
594. Remain/Stay/Be left (3757 candidates)
595. For /During /While (22323 candidates)
596. Extraordinary little tree (Verbal forms) (2075 candidates)
597. Most /Most of the / the most ... (8906 candidates)
598. To be dead/to die/death and LIFE (3035 candidates)
599. Such a strange trial ... 2/2 Mix of tenses (1931 candidates)
600. Such a strange trial ...1/2 Past perfect (2022 candidates)