1 . A major benefit of growing your own tomatoes is variety. If you visit a garden center, you will find seeds and small starter plants for yellow tomatoes, purple tomatoes, huge tomatoes, and even very small tomatoes.

    1    . The most important things are to give the plants plenty of water, well- draining soil, heat and light. It is best to grow tomatoes in a place that receives at least six hours of sunlight each day. Removing weeds will keep pests and diseases away while giving the plants enough nutrients to produce fruit.

Tomatoes grow best in soil with a pH level between 6.0 and 6.8. If the pH reading is lower than 6.0, you can add about 2 cups of dolomitic lime (石灰) into the soil for each plant.

If you want to grow really big tomatoes, try following these seven tips from expert growers: Select tomato seeds with names like Big Zac or Bull’s Heart.     2    .

Start seeds early indoors and re-plant them into larger containers several times before moving them outdoors.     3    , removing leaves from the bottom one- third of plants and burying stems up to the next set of leaves. This will produce stronger plants.

Remove new flowers that develop at the top of the plant when older fruits near the bottom begin to grow.     4    . Pay close attention! Observe the plants daily for posts and diseases. React quickly to prevent problems.

Remove the small growths where the plant’s stems and branches meet. This will prevent them from taking away nutrients and shading developing fruit under them.

    5     instead of letting them develop into a shorter, wider shrub (灌木).

Finally, water, fertilize and weed!

A．Plant them deep each time

B．Rich soil benefits the growth

C．Tomatoes are not difficult to grow

D．Skills are demanding in growing tomatoes

E．Cut back the plants to keep only one main branch

F．They are all genetically designed to produce large fruit

G．This will force the plant to produce fewer but larger tomatoes

2 . For breeding (繁殖) birds, timing is everything. Most species have just a narrow window to get the food they need to feed chicks. Now, after analyzing data that span from 1975 to 2017, a science team suggests that as the climate warms, birds are not only breeding earlier, but their breeding windows are also narrowed—some by as many as 4 to 5 days.

On average, the beginnings and ends of the breeding periods are occurring earlier in the year. However, the ends are shifting back faster than the beginnings, resulting in an average breeding window that is 1.7 days shorter in 2017 than it was in 1975. During that same period, Finland’s average temperature rose by 0.8℃, suggesting many bird species are actively responding to changing temperatures, Hällfors, who led the team, says.

“It’s good for the species if it’s able to follow the optimum conditions as the climate changes,” she says. However, the shorter breeding windows mean more birds are breeding earlier in the season—a risky time for chicks’ survival, especially if the weather turns suddenly cold. In addition, because many late-season species are shifting their breeding windows up, that could mean more competition for food and nesting sites early on, leaving some chicks to go hungry.

Lucyna Halupka, an ecologist at the University of Wroclaw, calls the study “a very important paper” because it’s one of the few ways to measure the breeding period duration. For 2 decades, she says, many scientists studying birds and climate change have looked only at the earliest, median (中间的), or mean laying dates for specific groups of birds. However, she reminds that because the study is limited to Finland, the findings may not apply universally; future studies should examine how breeding seasons move in other regions where the effect of climate change is different. They should also try to determine how shifting breeding windows affect population sizes, she says.

1. What did the scientists find?

A．The weather in Finland becomes warmer.

B．It is becoming more difficult for birds to breed.

C．The birds in Finland spend fewer days breeding.

D．There isn’t enough food for some chicks in Finland.

2. What does the underlined word “optimum” in paragraph 3 mean?

A．Exact.

B．Proper.

C．Changeable.

D．Dangerous.

3. What is the significance of the study according to Lucyna?

A．It is carried out in a different way.

B．It is helpful for people to protect the birds.

C．It opens a window for people to learn about these birds.

D．It demonstrates the living situation of the birds on earth.

4. What is the best title for the text?

A．Scientists Revealed the Secrets of Birds’ Breeding

B．Scientists Take Steps to Protect the Birds in the Wild

C．Birds Play a Role in Fighting Against Global Warming

D．Birds’ Breeding Windows Are Affected by Global Warming

3 . 阅读下面材料，在空白处填入适当的内容（1个单词）或括号内单词的正确形式。

Lijiang was made a World Heritage Site by UNESCO in 1997 for its historic town site, architecture and ancient water-supply system.

The Old Town of Lijiang,     1     (locate) in China’s Yunan province, is one of the last ancient towns that survive in China. Lying in     2     broad, fertile valley in the northwest of Yunan Province, Lijiang     3     (be) a commercial, cultural and political center of the Naxi (纳西族) people since Yuan Dynasty. Lijiang may leave an     4    (impress) on you for its beauty. The aging wooden buildings decorated with red lanterns and local musicians     5     (play) their old Naxi instruments in the time-worn streets show a lifestyle and culture that seem lost in time.

As UNESCO describes the village on its website, “The old Town of Lijiang,     6     is perfectly adapted to the uneven land form, has kept a historic townscape of high quality.” Its architecture is well known     7     combining the elements from several ancient cultures. Lijiang also possesses     8     we call the ancient water-supply system that still functions     9     (effective) today. However, with more and more tourists pouring in, it remains     10     (see) whether Lijiang can continue to keep its traditional lifestyle and culture.