The pressure of this gas pipe is greater than__________.
| A．the gas pipe | B．of the gas pipe |
| C．that of the gas pipe | D．those of the gas pipe |
—May I ask a question after class，Sir?
—, but not during my lunch break.
| A．I am sorry | B．Anytime | C．Go ahead | D．Certainly |
The scientists have made _______ possible for us to communicate with each other more easily.
| A．it | B．that | C．this | D．them |
You’d better your score and see if you have passed the exam.
| A．add up to | B．add to | C．add up | D．Add |
The second book ________ I want to read is Business at the Speed of Thought.
| A．which | B．that | C．what | D．As |
What the public is about is whether medical workers and scientists will be able to find a cure for the new disease in a short time.
| A．concerning | B．concern | C．concerned | D．to concern |