阿摩線上測驗
18. Sometimes, people are not conscious of the importance of health. Only when they lose health ______ its importance.
(A) they know
(B) that they know
(C) do they know
(D) they do know
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統計： A(10), B(23), C(95), D(16), E(0) #1760408
統計： A(10), B(23), C(95), D(16), E(0) #1760408