四、it类. Everyone knows that _______ is dangerous to play with fire, but _______ is difficult is to prevent children from playing with fire.
Absent for the traffic accident, I have always doubted he announced at the meeting.
____ is announced in today’s newspaper, we have launched another man-made satellite.
It's much easier to make friends _____you have similar interests.
As a mother of two young boys, she knows the difficulties of keeping kids ______.
—Little Daniel is watering the flowers! Why?—Well, I'm not feeling very well today—otherwise, I ________ it myself.