Select the most appropriate option to fill in the blank.

I ______ blood in the hospital tomorrow.

will donate

The correct option to fill in the blank is will donate.

The sentence is in the future tense, so the verb must also be in the future tense. The other options are in the past tense, present tense, or past perfect tense.

• Have donated is in the present perfect tense, which is used to talk about actions that have been completed in the past but have a connection to the present. For example, "I have donated blood twice this year."
• Was donating is in the past progressive tense, which is used to talk about actions that were in progress in the past. For example, "I was donating blood when I saw the accident."
• Had donated is in the past perfect tense, which is used to talk about actions that were completed before another action in the past. For example, "I had donated blood before I became a blood donor."