You were silly not _______ your car．

to lock

to have locked

locking

having locked

I don’t know whether you happen _______ ,but I’m going to study in the U．S．A．this September．

to be heard

to be hearing

to hear

to have heard

The flu is believed _______ by viruses that like to reproduce in the cells inside the human nose and throat．

causing

being caused

to be caused

be have caused

How many of us _______, say, a meeting that is not important to us would be interested in the discussion?

attended

attending

to attend

have attended

_______ to somebody, a British person often shakes hands with the stranger．

Introducing

To introduce

To be introduced

On being introduced

The bike needs _______, I am afraid．

repairing

to repair

repair

be repaired

Gary got to the manager’s office to report his plan, only _______ the manager went out．

to be told

to tell

being told

telling

_______ the right decisions _______ the future is probably the most important thing we’ll ever do in our lives．

Making; concerned

Make; concerning

To make; concerned

Making; concerning

It is easier to make a plan than _______．

carry it out

to carry it out

carry out it

carry out

I had nothing to do but _______ in bed, reading．

to lie

lie

lay

was lying