I into robots and used to make mobile phones as well as help with medical operations.
| A．have put | B．have been put | C．had put | D．had been put |
His mother left for work, __________ any of the dishes prepared for her.
| A．not eating | B．didn't eat |
| C．not having eaten | D．having not eaten |
The lady walked around the shops, __________ an eye out for bargains.
| A．keep | B．kept | C．keeping | D．to keep |
__________ the result of the examination, he went to the teacher's office to ask about it.
| A．Not having informed of | B．Having not informed of |
| C．Not informing of | D．Not having been informed of |
The news shocked the public, __________ to great concern about students' safety at school.
| A．having led | B．led |
| C．leading | D．to lead |
Have your ever been upset when __________ to yourself after your mobile phone battery runs out in the middle of a call?
| A．being left talking | B．left talking |
| C．being left to talk | D．leaving talking |