We students can _______ food and old clothes to the homeless people, and the teachers can __________ learning skills for the poor children.

Sometimes smiles around the world ______ be false, hiding other feelings like anger, fear or worry.

Where is my ball? I remember I put it here yesterday. –Youit in the wrong place.

Next to the pots ______, upon which the man could work metal.

What I want toto teenagers is that being addicted to the Internet will to some extent do harm to both mental and physical health．