Where is Grace?–She _____ inthe yard.

The light happened to _______.

The water changes into thick ice covering rivers and lakes in winter in Harbin. —— ＿＿＿＿ in Urumqi and children go skating on it then.

Not until all the fish died in the riverhow specious the pollution was

I have got a headache.—No wonder.You___in front of that computer too long