Most birds find it safe to sleep in the trees,butthey have eggs or young chicks,they don't use a nest.
| A． | why | B． | how |
| C． | unless | D． | where |
Russia’s cutting off the gas supply raised a major concern to the European Union, ______ a number of member states are increasingly dependent on one single supplier.
| A．whose | B．that | C．where | D．which |
US Apple decided to expand its business in China in response to an increasing demand ______ digital product.
| A．of | B．from | C．to | D．for |
We are confident that the step the Chinese government has taken to cope with the current crisis is ______ of great significance.
| A．what | B．those | C．that | D．one |
I witnessed the gate of the bank _______ open and many men entering it, but I couldn’t make them out in the darkness.
| A．force | B．be forced | C．forcing | D．being forced |
— I didn’t care about what other people thought about me.
— Well, you ________.
| A．should | B．ought to have | C．would have | D．could |