1. According to the interview, most college students preferred in-person courses over virtual classes, even while _____ the risks of contracting COVID-19.

(A) acknowledging (B) to acknowledge (C) has acknowledged (D) acknowledge

2. Diana Cole is a very talented artist _____ willingly experiments with new painting techniques.

(A) who (B) whom (C) whose (D) when

3. All volunteers are surveyed annually to ensure that they _____ with their assignments.

(A) will have satisfied (B) are satisfied (C) were satisfying (D) can satisfy

解析

1.【答案】(A)，分詞構句，前後主詞相同，省略主詞，主動，動詞用v-ing。

2.【答案】(A)，先行詞artist的關係代名詞是who。

3.【答案】(B)，be satisfied with = 對~感到滿意。