Select the appropriate conjunction to make the sentences grammatically correct.

1. ________ somebody is in need, do not hesitate to help.
a. unless c. therefore
b. when d. so

2. ________ I trust you, I will not keep my secrets from you.
a. whenever c. since
b. although d. so that

3. it was raining outside, _______ I took my umbrella
a. for c. although
b. since. d. so

4. it was a sunny day, _______ the wind was cold.
a. or c. because
b. and. d. but
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