At least how many tests were carried out by the scientists referred to in this passage（）

A. Please tell her to he there on time.
B. OK, dear.
C. May I speak to Ann, please
D. Well, that’s great.
E. Who’s that (speaking)
F. Can I take a message
G. we are going to plant trees.
H. Here you are.

A．He was offered a part-time job.
B．He was honored with a scholarship.
C．He helped his teacher construct a robot.
D．He helped in the computer laboratories.