9. Since 1980s, people have studied how to improve the information ________ of barcode symbol.
举一反三
- What is the question that remains to be studied? A: How to explain the long-term effects of the training. B: How to better improve older people's mental skills. C: How to attract more older people to take part in the training. D: How to increase older people's awareness of mental health.
- I__________ since three o’clock. A: studied B: have studied C: am studying D: studies
- ()How long __________ you __________ in the United States? A: have; study B: had; studied C: have; studied D: had; study
- How can people improve their spoken English?
- In an activity diagram, the merge symbol has the same shape as what other symbol? ( ) A: Transition arrows. B: Decision symbol. C: Initial state. D: Action symbol.