单项选择(每题1分)—Look, John’s fallen asleep at work!—Oh, he must have _____ late last night.
—If you like the new computer, I suggest buying it. —But it's really too expensive. I can't __________ it.
The Sun's activity has a strong __________ on the Earth.
The manager is said to have arrived back from Paris where he __________ some European business partners.
When he found many people were gathering there, he went to see what __________.
He __________ that until he __________ the directions once again.