多选题 Sleep actually occurs ______, though one may receive clues signaling its ______ for several minutes before one falls asleep.

A、 erratically
B、 inevitably
C、 instantaneously
D、 solace
E、 length
F、 onset

【正确答案】 C、F

【答案解析】[解析] ●though说明前后反义重复。
●第一空与for several minutes(几分钟)反义重复，填入一个表示“瞬间”的词。erratically 飘忽不定地/无规律地，inevitably必然地，instantaneously瞬间地。答案选C。
●第二空与occurs(发生)同义重复。solace安慰，length长度，onset开始。答案选F。