请教几个托福语法题

zsyf7575

1.In jazz music, a riff is a simple melodic figure,------and repeated several times.

(A) usually one or two measures lasted

(B) lasted one measure or two usually

(C) is lasting one or two measures usually

(D) usually lasting one or two measures

为何选（D）不选（A）或（B），lasting和 repeated 怎能用and并列呢？

2.At its center, the sun has a density of over a hundred times ------ and a temperature of 10 to 20 million degrees centigrade.

(A) that of water

(B) of water

(C) than that of water

(D) water

为何选（A）不选(C),times 在这不是比较吗,为何不用than,那times 是怎么个用法？

请大虾指教，谢了。

springqi

偶也是～～第一题选B，第二题选C！！ >////////////<

重剑无锋

语法问题请到语法区提问会有更好的解答哦。

consonant

1，如果A，少连词

选B，违背了谓语单一原则

2，X times that of a noun

表示倍数的固定用法

zsyf7575

thanks very much, especially Consonant: your explanation is very wonderful.