______ is widely acknowledged that all mankind is created ______.

I don’t know ______ with this problem. It’s too hard. — You can ask Mr Wang for help.

Linda’s father isn’t an engineer. Her mother isn’t an engineer, ______ .

Nanjing, the ancient capital of the six dynasties, is becoming ________ international city and attracts more and more foreign tourists every year.

Young man ! Don’t __________.It’s bad for your health.