He didn’t make________clear when and where the meeting would be held. [ ]

Hey, Jack! I’ve worked on this math problem half an hour ,but it’s got me nowhere. Could you give me a hand – ______ . I’m good at math.

Why was our foreign expert unhappy yesterday?— News about the earthquake in Japan _______ a feeling of homesickness . [ ]

People’s working efficiency usually decreases more or less when the temperature _________ 35℃ or even higher.

Indonesia_____ some 3,000 islandsstretching more than 2,000 miles from east to west.