Many manufacturers were accused of concentrating too heavily on cost reduction, often at the ______ of the quality of their products.
| A．expense | B．exposure |
| C．expansion | D．expectation |
Many people think it very difficult _______ English.
| A．to say | B．to learn | C．speak | D．for speaking |
The teacher asked the students __________ her _______ the word again.
| A．listen to; to read | B．to hear; say |
| C．to listen to; speak | D．to listen to; pronounce |
Remember ______ the book here tomorrow.
| A．bring | B．to bring | C．take | D．to take |
---Let's have a rest, shall we?
--- Not now. I don't want to stop _______ the letter yet.
| A．write | B．to write | C．writing | D．and write |
---This physics problem is too difficult. Can you show me __________, Wang Lin?
--- Sure.
| A．what to work it out | B．what to work out it |
| C．how to work it out | D．how to work out it |