__________ ups and downs in the past four years，Bob finally succeeded in extending his business overseas.
| A．Experienced | B．To experience |
| C．Having experienced | D．Experiencing |
How did it _____ that the two men arrived to address the same meeting at the same time.
| A．fall out | B．take place | C．get around | D．come through |
The authorities declared that because of the war petrol was _____ and had to be rationed (定量供应).
| A．inadequate | B．rare | C．lacked | D．scarce |
His name was on the _____ of my tongue, but I just couldn't recall it.
| A．end | B．point | C．edge | D．tip |
Feudal landlords, and imperialists are in no way more _____ than wolves.
| A．reasonable | B．regardless | C．ridiculous | D．rational |
She was putting on her watch when the _____ broke and it fell to the ground.
| A．belt | B．strap | C．tie | D．string |