1.It's important to learn how the whole system works. Sometimes, ________， it's the details that interest us the most.

A. therefore  B. meanwhile  C. furthermore  D. though

2. —How come everything tastes bitter?

—Well, things ________ taste different to you when you are suffering a cold.

A. may  B. should  C. must  D. would

3.—How was the professor's lecture?

—Impressive. Thank you so much for giving me a lift during the rush hours. If not, I ________ the lecture today.

A. couldn't attend  B. might not have attended

C. mustn't have attended  D. can't have attended