了解です。 A 1 that 2 that 3 who 4 what B 1 (that you cooked was delicious.) 2 (whom Donna is talking to?) 3 (whose parents are both doctors.) 4 (that was too big for him.) C 1 (anybody who can play the drums?) 2 (The hotel we stayed at was) 3 (some truth in what John said) 4 (Is there anything I can do) ⇨ anything/単数扱い --------------------