The purpose of new inventions is _______ life more difficult, but to make it easier.
Her husband is a great cook. So she can enjoy _____ food every day.
—Would you mind opening the window? —____. Look at the heavy haze (霾) outside.
It’s ____ useful book. And ____ book is popular with students.
—Is your headache getting _______? —No, it’s worse.
—Which is your new neighbor, Liu Hua? —The man _______ T-shirt is red.