Skip to content
Prep
Freely
Home
TOEFL
IELTS
Guides
Log in
Sign up
P
Account
Profile
My progress
Settings
Log out
TOEFL
/
Listening practice
/ Section TZ4A
Listen to an Academic Talk
Listen to part of a talk in an immunology class.
Listen
28. What does the speaker suggest about obstacles in science generally?
A
They arise most often where procedures are complicated
B
They can consist of a way of thinking that is not yet available
C
They are recognised only long after they are overcome
D
They are usually removed by better instruments