问题 选择题

氢化锂(LiH)是一种离子化合物,它与水反应生成H2。以下叙述正确的是(   )

A水溶液呈酸性                      B.H-与He的核外电子排布相同

C.H-可以被还原成氢气                D.H2O在反应中作氧化剂

答案

BD

LiH与H2O的反应为:

====LiOH+

单项选择题

Shoppers who carefully plan their visit to the grocery store can save money on their grocery bills. Shopping when not (61) , sticking to their grocery list, and (62) a few simple rules will cut down the grocery bill.

Shoppers should visit the grocery store on a full stomach by planning their trip (63) after a large meal. If that’s not (64) , they should find something (65) to eat on while preparing a grocery list. Most shoppers are less likely to buy extras when they are not troubled by (66) .

Although having a list and (67) to it is the most important factor in saving money, (68) must prepare lists wisely in order to (69) . A carefully planned list should (70) in season produce and any items on (71) or discounted through coupons. Many special buys are announced through the local newspapers, so buying the "grocery issue" is (72) the money you spend. (73) , it’s important to remember that many newer, more expensive products first offered through coupons may not (74) enough savings for shoppers to give up products they usually buy.

Now that the shopper has (75) the grocery list, it’s time to leave for the store. However, no preparations are complete without a pocket calculator or a piece of paper and a (76) to figure costs.

Once at the store, the shopper who wants to save money should follow a few more rules. The shopper should not stay (77) than necessary because bills go up each minute the shopper is in the store. So, (78) a time limit and a cost limit can hold down the (79) . Of course, the shopper should stick strictly to the (80) and not buy any extras. If the grocery list is a short one, shoppers can use the small hand-held basket instead of the roomy grocery cart.

63()

A.shops

B.hunger

C.money

D.work

多项选择题