It will be difficult for a robot the same as humans.

We came home and found her ________ on the sofa.

you find the missing couple in the mountainyesterday——No, but we _____ to get in touch with them eversince.

My old father began to study computer science at the age of sixty in order that he might ________ times.

The whole nation was ______ by the young generation’s excellent performances when the disaster happened.