某尽头式货物线有效长465m，按14.3m计算其容车数是（）。A.30辆 B.31辆

The doctor said that you are _________, so you’d better have a healthy diet and try your best to lose your weight.

A．thin

B．overweight

C．slim

D．energetic

常温下，下列各组离子在指定溶液中一定能大量共存的是

A．能溶解Al₂O₃的溶液：Na⁺、K⁺、HCO₃^-、NO₃^-

B．0．1mol·L^-1Ca(ClO)₂溶液：K⁺、Na⁺、I^-、Cl^-

C．能使甲基橙显红色的溶液：K⁺、Fe²⁺、Cl^-、NO₃^-

D．加入KSCN显红色的溶液：Na⁺、Mg²⁺、Cl^-、SO₄^2-

原发性免疫缺陷病的主要特征是（）

A.出血

B.反复感染

C.特殊面容

D.智力低下

E.生长发育迟缓

快速压力蒸汽灭菌后的物品存放不能超过（）

A、6小时

B、4小时

C、12小时

D、24小时

The short-run supply curve to a firm operating under perfect competition is most accurately described as the segment of the:（）

A. marginal cost curve below the average total cost curve.

B. average total cost curve above the marginal cost curve.

C. marginal cost curve above the average variable cost curve.