The ship_________ at 8:30, but it is almost 9:30 now.

• A、must have arrived

• B、would have arrived

• C、could have arrived

• D、should have arrived

53.________.

What does the text mainly discuss about the Internet?

• A、Its influence on school teachers.

• B、Its effect on high school students.

• C、Its success in high school teaching.

• D、Its achievements in school research.