154. Using renewable energy is a simple idea, but ______ we find it hard to put into practice.
| A．one | B．what | C．which | D．That |
As________tourist attraction，the Summer Palace does have________strong attraction to visitors from home and abroad.
| A．the；/ | B．the；a |
| C．a；/ | D．a；the |
—Sorry，it’s already 6 o’clock.I have to be off for an appointment.
—OK.________.
| A．It couldn’t be better | B．You really have me there |
| C．Let’s call it a day | D．Take your time |
Honesty is a virtue________greed is an evil，as the saying goes.
| A．while | B．when |
| C．as | D．and |
Parents，of course，will do everything they could to________their children from harm.
| A．defend | B．convince |
| C．overcome | D．reduce |
I know it’s normal for such a thing to happen，but we________it if we’d been more careful.
| A．need have avoided | B．could have avoided |
| C．will have avoided | D．had avoided |