青藏高原上的主要农作物有( ) A．青稞、小麦 B．小麦、玉米 C．青稞、玉米

--- Lucy seems in low spirits.

--- Yes, all her efforts were ____ and no one was interested in her invention.

A．in need

B．in vain

C．in place

D．in use

限额设计是设计阶段控制造价的有效方法，下列关于限额设计表述中正确的是( )。

A．限额设计的目标值是由建设单位提出的

B．如发现某项费用指标超出的投资限额，可等到设计概算编出后再调整解决

C．设计控制限额一经分解下达，不可修改

D．其总额度一般只下达直接工程费的90%

The following data sufficiency problems consist of a question and two statements, labeled (1) and (2), in which certain data are given. You have to decide whether the data given in the statements are sufficient for answering the question. Using the data given in the statements plus your knowledge of mathematics and everyday facts (such as the number of days in July or the meaning of counterclockwise), you must indicate whether.

Is the value of x³y-x²y²+xy³ equal to 0 ？（）
(1) x=0
(2) y=0

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

请你为本市全面建设小康社会提两个建议。

________________________________________________________________________________

牙 * * 形成（）

A.牙釉质

B.牙本质和牙髓

C.牙本质

D.牙骨质

E.牙槽骨