complex；ambition；recall；involve；comfort；cite；grasp；motivate；depress；expose

（1）I

recalled

recalled

that he had mentioned the problem once.
（2）What he said was too

complex

complex

for me to understand.
（3）At last he had realized his life's

ambition

ambition

.
（4）The old lady often

comforts

comforts

those who are in trouble.
（5）This is similar to the example

cited

cited

above.
（6）Inventions typically

involve

involve

minor improvements in technology.
（7）You have first got to

motivate

motivate

the children and then to teach them.
（8）He

exposed

exposed

the plan to the newspapers.
（9）A man who

grasps

grasps

at too much may lose everything.
（10）His mother was

depressed

depressed

by the sad news.