In this mountain area, two volcanoes have been _____ lava (熔岩) for a week. It is very dangerous.

When lava cools, it becomes A: liquid. B: water. C: smoke. D: hard.

Lava bursts out where there is A: a crack in the earth. B: a mountain by the sea. C: a big fire. D: steam and gas.

volcano is to lava as () A: geyser is to water B: fault is to tremor C: glacier is to fissure D: avalanche is to snow E: cavern is to limestone

The great size of the volcanoes and the ______ of their lava flows is considered an indication that the crust of Mars is fixed. A: explosion B: exploit C: extent D: exposure

In this mountain area, two volcanoes have been _____ lava (熔岩) for a week. It is very dangerous. A: evaluating B: examining C: ejecting D: equipping

The first species to live on new land, such as that formed from volcanic lava, are called A: clomax community. B: keystone species. C: foundation species. D: pioneer species. E: parasite.

-todo el mundo se lava los dientes después de desayunar en España.-pues yo no, yo_______ me lavo los dientes y _______ desayuno A: Luego/primero B: Luego/después C: Primero/luego D: Antes/después